BBC Micro:Bit V2.2 Go Kit

Official Raspberry Pi 4 Model B 4GB RAM The Raspberry Pi 4 Model B 4GB is a compact and versatile single-board computer that provides desktop-level performance in a credit card-sized device. The RPI 4B is powered by a Broadcom Quad-Core Cortex-A72 (ARM v8) 64-bit SoC that runs at 1.5GHz and has 4GB of LPDDR4-3200 SDRAM for efficient multitasking and basic desktop programs. This device is designed for a wide range of DIY projects, including media centres, file servers, robotics, and smart home systems. The Raspberry Pi 4B 4GB supports dual 4K displays ( 4K@30Hz ) through its micro-HDMI ports, making it perfect for high-definition video and creative endeavours. It has dual-band WiFi 2.4 GHz and 5.0 GHz IEEE 802.11ac , Bluetooth 5.0 , and Gigabit Ethernet for a consistent connection. It also features two USB 3.0 connections and two USB 2.0 ports to connect devices. The Raspberry Pi 4 4GB is popular among programmers and makers. It comes with native Python support , making it a fantastic platform for coding education and automation project development. It is capable of running both 32-bit and 64-bit operating systems , offering versatility for different uses. Whether for teaching, prototyping, or creative projects, it serves as a potent and affordable computing option. Shop Raspberry Pi 4 4GB Full Kit – Plug & Play Setup Affordable power for your projects – Raspberry Pi 4 2GB ! What makes this model Great? The speed and performance of the new Raspberry Pi 4 4GB are a noticeable improvement from earlier models. For the first time, the Raspberry Pi Foundation has created a complete desktop experience. Whether you're editing documents, browsing the web with multiple tabs open, managing spreadsheets, or creating a presentation, you'll find the experience smooth and familiar. It is a more energy-efficient and cost-effective machine. Features Broadcom 2711 Quad-Core Cortex A72 @ 1.5GHz delivers 20% faster performance with improved power and thermal efficiency. Dual micro-HDMI outputs support dual 4K displays with hardware video decode at 4Kp60 (H.265, H.264, MPEG-4). Dual-band WiFi (802.11b/g/n/ac) on 2.4GHz & 5GHz with advanced PCB antenna for robust wireless connectivity. Bluetooth 5.0 offers an extended range of wireless peripherals. Upgraded USB 3.0 Ethernet provides wired speeds up to 10x faster than previous models. 2 USB 3.0 and 2 USB 2.0 ports enable versatile peripheral connections. 40-pin GPIO header is fully backwards-compatible with earlier Pi models. Optional PoE support is available, with PoE header pins designed to work with proper standoffs. Comparison Table Raspberry Pi 4 Model B Raspberry Pi 5 Raspberry Pi 3 Model B+ Price (INR) ?3599 VIEW ?5129 VIEW ?3649 VIEW Processor 1.5GHz Quad-Core ARM Cortex-A72 2.4GHz Quad-Core ARM Cortex-A76 1.4GHz Quad-Core ARM Cortex-A53 RAM 1GB, 2GB, 4GB, 8GB LPDDR4 2GB, 4GB, 8GB, 16GB LPDDR4 1GB LPDDR2 Wi-Fi Dual-band 802.11ac Dual-band 802.11ac Dual-band 802.11ac Bluetooth 5.0 5.0 4.2 USB Ports 2× USB 3.0, 2× USB 2.0 2× USB 3.0, 1× USB 2.0 4× USB 2.0 Ethernet Gigabit Ethernet Gigabit Ethernet Gigabit Ethernet Video Output 2× Micro HDMI (4Kp60) 2× Micro HDMI (4Kp60) 1× HDMI (1080p) GPIO Pins 40 40 40 Storage MicroSD (SDXC up to 2TB) MicroSD (SDXC up to 2TB) MicroSD (SDHC) Power Supply USB-C USB-C Micro USB Click for Complete Raspberry Pi Kits – Learn, Build, and Innovate! Pin Diagram:

Waveshare UGV Rover ROS 2 Open-source 6 Wheels 4WD AI Robot With Jetson Orin Nano 4GB Kit, Dual controllers, 360° Flexible Omnidirectional Pan-Tilt Waveshare UGV Rover ROS 2 Open-Source 6-Wheel 4WD AI Robot is a powerful mobile robotics platform designed for Jetson Orin series boards. Built for advanced AI, perception, and autonomous navigation tasks, it features a rugged 6-wheel 4WD design, dual controllers, and a 360° flexible omnidirectional pan-tilt system for full-range vision. Ideal for research, prototyping, and robotics development, this UGV offers seamless ROS 2 integration and high performance for real-world robotic applications Features Supports Pan-Tilt drag-and-drop control via mouse or touch panel of the laptop, providing a better control experience as FPS games Powered by Jetson Orin series computer Supports Jetson Orin Nano 4GB Kit, provides up to 20 TOPS AI Performance. High-speed reading/writing, to meet the development needs of large AI projects Advanced AI Recognition & Tracking Based on OpenCV, supports color recognition and automatic targeting with one-key Pan-Tilt control and auto LED lighting. Expandable for additional AI functions. Face Detection & Recognition Automatically captures photos or records videos when a face is detected, providing enhanced security and AI interaction. Cross-Platform Web Control No app installation required! Simply connect via a web browser on mobile, tablet, or PC. Supports WASD keyboard shortcuts and mouse control for seamless navigation. WebRTC real-time video transmission Adopts Flask lightweight web application, based on WebRTC ultra-low latency real-time transmission, using Python language and easy to extend, working seamlessly with OpenCV Features at a glance Multiple Autonomous Navigation Modes UGV Rover supports multiple autonomous navigation modes, allowing it to navigate complex environments with precision. Whether following predefined paths, avoiding obstacles, or performing AI-assisted route planning, the robot adapts intelligently to real-world terrains. Dimensions

SmartElex Micro:Bit Gator Microphone Accessory Board SmartElex Micro:Bit Gator Microphone Accessory Board is a compact audio input module designed for sound-based projects using the BBC micro:bit. It enables students, hobbyists, and educators to capture and measure sound levels, making it easier to explore audio interaction, environmental monitoring, and voice-triggered responses. This board helps simplify sound detection tasks without complex circuitry, making it ideal for classroom STEM learning, beginner prototyping, and creative electronics projects where ease of use matters. This gator microphone micro:bit accessory integrates seamlessly with the micro:bit ecosystem through alligator clip connections, allowing quick setup for sound-reactive experiments, robotics projects, and IoT prototypes. It provides a reliable interface for building projects such as noise meters, sound-activated indicators, interactive art, or classroom activity monitors. Whether used in a school environment or by independent makers, it offers a straightforward way to introduce audio sensing to microcontroller projects while encouraging hands-on learning and innovation. Features: Fully compatible with gator:bit and micro:bit audio projects Built-in ADS1015 ADC for accurate sound level measurement Supports multiple modes: Single-Shot, Continuous Conversion, and Duty Cycling Single-ended analog input configuration with adjustable full-scale range 12-bit differential / 11-bit single-ended resolution for precise signal capture Sample rate options from 128 Hz to 3.3 kHz for varied recording needs Low-power operation with typical draw between 150μA–200μA Communicates via I2C with default address 0x48 Integrated electret microphone with omnidirectional pickup pattern Frequency response range of 20 Hz to 16,000 Hz for everyday sound detection Includes LMV324 Op-Amp for stable and amplified audio signal processing Wide operating voltage support from 2.0V to 5.5V, suitable for microcontrollers Designed for STEM classrooms, prototyping, IoT sensing, and audio experiments

ACEBOTT QD108 FootBall Arena Kit For TinkerBott V1.1 The ACEBOTT QD108 Football Arena Kit for TinkerBott V1.1 is an engaging and interactive robotics playground designed to bring fun, competition, and learning together. Specifically created for the TinkerBott V1.1 platform, this football arena set lets users build, program, and control robots to play dynamic football matches. With modular components and easy assembly, the QD108 kit enhances STEM learning, encourages teamwork, and provides a hands-on way to explore robot movement, strategy, and coding in action. Features Football Arena Setup – Includes all parts needed to build a complete robotic football arena for exciting match play. Modular Design – Easy to assemble and reconfigure, perfect for classrooms, competitions, and home activities. Enhances STEM Learning – Combines robotics, coding, and team strategy for an educational play experience. Designed for TinkerBott V1.1 – Seamlessly integrates with the TinkerBott robot platform for smooth performance. Encourages Creativity & Fun – Lets users develop game tactics, program robot behaviors, and compete in challenges. Perfect for Group Activities – Ideal for clubs, classes, and family projects where teamwork and robotics meet.

ACEBOTT QE201 Wooden Board for ESP32 Basic Starter Kit (Expansion Pack) The ACEBOTT QE201 Wooden Board for ESP32 Basic Starter Kit (Expansion Pack) is a practical learning expansion designed to enhance the core ESP32 starter kit with real-world, hands-on projects. Built with wooden structural assembly support, this expansion enables users to create 37+ interactive projects such as a Smart Butterfly, Electronic Piano, Smart Watermelon Fan, Smart Barrier, and Smart Trash Can. It is fully compatible with Arduino and Blockly programming, making it ideal for beginners who want to learn electronics, coding, and automation in a simple and humanized way. The main core function of this expansion pack is to transform basic electronic concepts into physical smart models, helping users understand how embedded systems work through engaging and easy-to-build projects. Features: Supports 37+ practical expansion projects for ESP32 learning Designed for wooden structural assembly to build physical smart models Compatible with ACEBOTT QE201 ESP32 Basic Starter Kit Works with both Arduino and Blockly programming platforms Includes smart applications like Smart Butterfly, Electronic Piano, Smart Fan, Smart Barrier, Smart Trash Can Beginner-friendly design for easy assembly and understanding Humanized learning approach for interactive STEM education Suitable for students, hobbyists, and training institutes

ACEBOTT QD028 ESP32 2-in-1 Football & Battle Car Robotics Kit ACEBOTT QD028 2-in-1 Football & Battle Car Kit is a unique and exciting programmable robotics kit built around the powerful ESP32 controller. Designed for hands-on learning and creativity, this kit lets users build and customize a dual-mode robot that switches seamlessly between football player and battle car modes. With modular expandability and intuitive programming support, the QD028 is perfect for STEM classrooms, home learning experiences, activities, and friendly competitions. Features 2-in-1 Dual Gameplay Modes – Switch instantly between Football Mode and Battle Car Mode for endless fun and creativity. Powered by ESP32 Controller – Supports Wi-Fi and Bluetooth, enabling smart control, coding, and expandable IoT possibilities. Modular Assembly Design – Easy-to-build, kid-friendly components that encourage hands-on learning and fast reconfiguration. STEM-Focused Learning – Teaches robotics, electronics, coding, and problem-solving, perfect for classrooms and home education. Programmable with Multiple Platforms – Supports Arduino IDE and ACECode (Scratch-style coding) for all learning levels. Durable, Competition-Ready Build – Designed for activities, challenges, and competitions with stable control and smooth movement.

Holybro S500 V2 DIY Drone Kit (Included Motor, Prop and ESC) The Holybro S500 V2 DIY Drone Kit (Included Motor, Prop and ESC) is a complete DIY drone kit designed for builders and enthusiasts who want a reliable, high-performance UAV platform right out of the box. This all-in-one kit includes quality motors, propellers, Electronic Speed Controllers (ESCs), and a durable S500 V2 frame, giving you everything you need to assemble a capable multirotor drone with confidence. Whether you're a hobbyist looking to build your first drone or a professional seeking a customizable platform for experimentation and upgrades, this kit provides a solid foundation. Engineered for ease of assembly and dependable flight performance, the Holybro S500 V2 DIY Drone Kit combines balanced thrust, stable handling, and efficient power delivery for smooth flight characteristics. Its thoughtfully selected components ensure compatibility and optimized performance, making the build process straightforward while offering room for future enhancements. From casual flying to aerial photography and DIY experimentation, this kit empowers you to bring your custom drone ideas to life with quality and precision. Features: Complete DIY drone kit including frame, motors, propellers, and ESCs for easy assembly. Durable S500 V2 frame designed for stable and reliable multirotor performance. Balanced propulsion system delivers smooth thrust and efficient flight. Supports customization and upgrades with compatible flight controllers and accessories. Suitable for beginners learning drone assembly as well as advanced UAV projects. Ideal for DIY builds, aerial experimentation, and educational drone applications.

DFRobot Gravity 7/24 Industrial Analog pH Sensor Meter Kit for Arduino The DFRobot Gravity 7/24 Industrial Analog pH Sensor Meter Kit for Arduino is a high-precision Analog pH Sensor designed for professional and industrial applications requiring continuous pH monitoring. This Arduino pH Sensor uses an industrial-grade glass membrane electrode with low impedance, delivering fast response, excellent thermal stability, and stable performance over long periods. It supports a full measurement range of 0 pH to 14 pH with linear voltage output, ensuring accurate and reliable readings. The sensor integrates easily through a BNC connector and PH2.0 interface, allowing direct connection to any Arduino analog input. Its reference system, based on Ag/AgCl gel electrolyte with a PTFE membrane, provides strong anti-pollution characteristics and prevents clogging, making it an ideal industrial pH sensor for Arduino for water treatment systems, environmental monitoring, and laboratory analysis. Attention: The probe's bottle top contains protective fluids (3.3mol/L KCL). Even if the bottle cap is tightly fastened, some protective liquid may leak around it, resulting in white crystals. However, as long as the bottle top contains protective liquid, the probe's life and accuracy will be unaffected. Please use it with confidence. It is recommended that the white crystals be returned to the bottle cap's protective liquid. Features Industrial-grade Analog pH Sensor for accurate measurement Compatible with Arduino and other microcontrollers Measures pH range from 0 to 14 Fast response with high stability BNC connector for secure sensor connection Plug-and-play PH2.0 analog interface Built-in power indicator LED Suitable for long-term online monitoring Low maintenance and long sensor life Ideal for water quality and lab applications Applications Water Quality Surveillance Aquaculture

NVIDIA Jetson Orin NX 8GB RAM 70 TOPS AI Embedded Module T801 AI Developer Kit The NVIDIA Jetson Orin NX 8GB RAM 70 TOPS AI Embedded Module T801 AI Developer Kit is a compact yet powerful edge AI platform built for developers and innovators who need serious computing performance in a small footprint. Equipped with 8GB RAM and delivering up to 70 TOPS of AI performance, this module enables real-time machine learning, computer vision, and autonomous processing directly on the device—without depending on cloud connectivity. It is perfectly suited for robotics, smart surveillance systems, industrial automation, and advanced IoT solutions. With full support for popular AI frameworks like TensorFlow and PyTorch, along with NVIDIA’s JetPack SDK, the kit streamlines development, testing, and deployment of intelligent systems. Whether you are prototyping an AI concept or building a production-ready solution, this developer kit offers the performance, flexibility, and reliability required for next-generation embedded AI applications. Hardware Overview: Applications: 1. Practical Application in Security Monitoring Scenarios 2. Practical Application in Smart Gas Station 3. Practical Application in Smart Petroleum Providing simultaneous assistance for channel video analysis. Provide support for smoke, fire, personnel area monitoring, fall detection, safety helmet recognition, tools, gauges, oil level, and valve direction. 4. Practical Application | Identification of Unidentified Objects in Power Transmission Providing simultaneous support for four-channel video analysis Unidentified object recognition, fireworks, and engineering vehicles. Subsequent additions, aberrant insulators, pins, bird spikes, Features: Built on NVIDIA Jetson Orin NX architecture 8GB RAM for smooth AI model execution Up to 70 TOPS AI performance for real-time inference Optimized for edge AI and embedded systems Supports TensorFlow, PyTorch & NVIDIA JetPack SDK Low power consumption with high computational efficiency Ideal for robotics, smart vision, and industrial automation applications

NVIDIA Jetson Nano Development Kit (Alternative of B01 Kit) The NVIDIA Jetson Nano Development Kit is an advanced AI computing platform, designed as a powerful and flexible alternative to the Jetson Nano B01 Kit. Featuring compatibility with both Jetson Nano and Jetson Xavier NX core modules, this development kit maintains almost the same I/O interfaces, size, and thickness as the original Jetson Nano Developer Kit (B01), making it an ideal upgrade solution. With its robust computing power and versatile connectivity, it is suitable for a wide range of AI applications including image classification, object detection, segmentation, speech processing, and more. Whether you are working on edge AI projects or seeking a Jetson Nano Kit Alternative, this development kit empowers developers to harness the full potential of NVIDIA Jetson Nano Development Kit capabilities while offering seamless module upgrades. Features: Compatible with Jetson Nano Core Module and Jetson Xavier NX Core Module Designed as a Jetson Nano B01 Alternative with similar I/O ports, size, and form factor Easy upgrade path by swapping the core module for enhanced AI performance Supports advanced AI tasks like image classification, object detection, segmentation, and speech processing Provides powerful GPU-accelerated AI computing for edge AI and embedded applications Compact and efficient design for seamless integration into custom projects Ideal for developers looking for a Jetson Nano Kit Alternative with extended flexibility Fully utilizes the capabilities of the NVIDIA Jetson Nano Development Kit ecosystem

Seeed Studio XIAO nRF52840 Module & Wio-SX1262 Kit for Meshtastic The Seeed Studio XIAO nRF52840 Module & Wio-SX1262 Kit is a powerful combination designed for modern IoT and wireless networking projects. Featuring the nRF52840 module and SX1262 transceiver, it supports BLE 5.0 and LoRa (862-930MHz) for reliable, long-range communication with low power consumption. This versatile kit is perfect for applications such as Meshtastic, environmental monitoring, sensor networks, asset tracking, and educational or innovative experiments. It's compact design and robust features make it an ideal solution for developers, makers, and students exploring connected device projects. Features: Versatile Microcontroller: Incorporate the Nordic nRF52840 chip with FPU, working up to 64 MHz, mounted several development ports, supported by Arduino, CircuitPython, and Micropython. Long-range: LoRa on the Semtech SX1262 supports the 868/915 MHz bands, providing powerful performance. Dual-core communication: It supports Bluetooth and LoRa dual modes, allowing for cross-domain interconnection. The integrated antenna is 8mm × 22mm × 23mm. Applications: Meshtastic Node&Router: An extremely compact node that may be used as a portable device or a stationary router to expand the Meshtastic network. LoRa/LoRaWAN Sensor: A little LoRaWAN sensor, excellent for those new to LoRa/LoRaWAN. When paired with a GPS module (such as the XIAO L76K), it can be used to track the movement of logistical vehicles, livestock, and important equipment. LoRa's long-distance coverage (2-5 km in urban areas and more than 10 km in suburban areas) can help to lower the cost of base station placement. Hardware Overview of XIAO nRF52840 Module: Pinout Diagram: Hardware Overview of Wio-SX1262: Pinout Diagram:

160mm Aluminium CPU Heatsink This is a 160mm Long Aluminium Water Cooling Block Liquid Cooler Waterblock Radiator-GPU CPU Cooling Heatsink.  The CPU heatsink has a solid construction and choosing aluminium as the raw material is a wise option for heat dissipation. The surface of the heatsink is treated by the method of silver oxidation. It is suitable for cooling graphics GPU, motherboard Northbridge Southbridge CPU, graphics; semiconductor cooling piece, industrial cooling, etc. The CPU heatsink is a water cooling block where the heat dissipation method of that the liquid conducts the cold and heat exchange. Features: High Thermal Conductivity: Made from aluminum, which is an excellent conductor of heat. Large Surface Area: The 160mm size provides a large surface area for effective heat dissipation. Lightweight: Aluminum is lightweight, making it suitable for various applications without adding significant weight. Durable: Resistant to corrosion and can withstand high temperatures. Easy Installation: Designed for easy mounting on CPUs. Efficient Cooling: Helps maintain optimal operating temperatures and prevent overheating. Applications: Computer Systems: Used to cool CPUs in desktops, servers, and workstations. Gaming Rigs: Helps maintain optimal temperatures in high-performance gaming PCs. Industrial Equipment: Applied in industrial computers and control systems to prevent overheating. Power Amplifiers: Used in audio and RF power amplifiers to dissipate heat. LED Lighting: Helps manage heat in high-power LED lighting systems. Consumer Electronics: Used in various electronic devices that require efficient thermal management.

Original Meta Quest 3S VR Headsets 128GB Get ready to step into the future with Quest 3S! This game-changing leap makes mixed reality more accessible than ever. We’re thrilled about the endless possibilities it unlocks—are you? Unlock Thousands of Mind-Blowing Immersive Experiences! Experience MR gaming, fitness and entertainment, including your favourite apps, like Facebook, Instagram and WhatsApp—all within the headset. Entertainment: Dive into an unmatched viewing experience like never before. Gaming: Don’t just play—immerse yourself in your favourite games with Meta Quest. Sports: Feel the thrill of courtside action, no matter where you are. Fitness: Crush your fitness goals while having fun, all from the comfort of your home. Get Hands-On Feel the action like never before with precision controllers that move as naturally as you do. Plus, with upgraded tracking, you can ditch the controllers and dive in hands-free! Your Gateway to Gaming Pick your perfect Meta Quest and explore a constantly expanding catalog of games designed to keep you coming back for more! Features 4.5X better resolution and color than Quest 2 for clearer, more vibrant visuals. 96° x 90° field of view with sharp detail of ~20 pixels per degree and ~773 pixels per inch. Powered by Snapdragon XR2 Gen 2 chipset and 8GB RAM for faster, smoother performance. Glasses spacer included for comfort during long use. Precision controllers that feel natural and controller-free tracking for hands-free use. Blends apps and games into your surroundings for a fun mixed reality experience. Batman: Arkham Shadow game included with 128GB and 256GB models. 3-month Meta Quest+ trial for extra games and content. Comes with a 1-year limited warranty. Introducing Meta Quest 3S

Official Arduino Portenta Proto Kit VE for Advanced Prototyping The Official Arduino Portenta Proto Kit VE (Vision Environment) is a comprehensive development solution tailored for creating functional prototypes that leverage machine vision and environmental monitoring. Designed with a suite of integrated Arduino Pro components, this Stem kit empowers developers to rapidly build and test advanced applications such as object recognition, people counting, air quality monitoring, and industrial automation. Its robust sensing capabilities and built-in connectivity, enabled by the Arduino Pro 4G Module, ensure seamless data processing and cloud integration. Ideal for innovators and professionals, the Portenta Proto Kit VE bridges the gap between concept and commercialization by streamlining the path from prototype to final product. Applications: Predictive maintenance with Nicla sensors and cloud algorithms to minimize downtime Intruder detection using face recognition, motion sensing, and real-time alerts Environmental monitoring of air quality, noise, and other parameters Machine vision for object recognition, motion detection, and people counting Logistics tracking with environmental sensing and cloud-based location data EV charging station prototype with remote management and analytics High-speed test rigs for sensor calibration, load testing, and real-time analysis Features: Portenta H7: High-performance dual-core microcontroller ideal for advanced data processing and edge machine learning applications. Portenta Mid Carrier: Enhances expandability and connectivity, providing professional-grade interfaces for robust prototyping setups. Nicla Vision: Ultra-compact color camera module with onboard AI capabilities, enabling real-time image processing at the edge. Nicla Sense Env: Low-power sensor board that monitors air quality, temperature, humidity, pressure, and more for indoor and outdoor environments. Modulino Nodes: Modular and compact units for rapid deployment of sensing and actuation tasks, ideal for quick iteration and development. 4G GNSS Module Global: Ensures global cellular connectivity and location tracking via GNSS, enabling remote and mobile applications. Arduino Cloud for Business Voucher: Includes a 3-month subscription for seamless cloud-based data storage, visualization, and remote device management. All Required Accessories Included: Comes complete with power supply, cables, and connectors, everything you need to start building right out of the box.

DIY Solar Powered Ferris Wheel Kit Along with teaching your kid about assembly, motors and batteries, add a perfect showpiece of your kid's invention at your home! Learn to harness the power of solar to ferry the wheel which can be converted into a solar powered Fan. Solar Ferris Wheel is a creative solar toy. It uses sunlight to generate electricity and drives the blue turntable to rotate tirelessly. It is vivid and creative, It can be used to effectively decorate your ship and entertainment platform, and also great for living room, bedroom, office and so on. Can be used as a small decorative item in the home, indoors or outdoors. It is a handmade model, and all made of environmentally friendly abs plastic materials, the solar energy Ferris wheel can be used as a toy for children, and it can also be used as a gift for children. Features: It's an educational toy set which is great for kids training their intellectual development, hands-on brain, interest in culture, grip, hand-eye coordination. Parents can DIY with their kids and promote their parent-child communication in the process of assembling. It is very easy to install and does not require special tools. Lightweight and portable, unisex for all ages The finished toy can turn with sunshine . Under direct sunlight, the use of solar energy, can be slowly rotated (rainy days and indoor solar function can not be used) Exquisite workmanship, but also as a peculiar and unique crafts indoors. Package includes several sets of white pillars , and vary in length , you can choose the appropriate combination according to personal preference , to produce a dozen different combinations of rotating disk , you can install the 8 ball can also be installed 4 balls. Also check Windmill DIY Kit offered by ROBOCRAZE. The DIY kit is designed for children aged 3 and above, providing a fun and educational project to construct a windmill. It includes components such as a 2-Pin SPST Switch, 9V battery with a battery cap, toy motor, and a small plastic fan. The windmill can also function as a mini fan.