SPECIFICATION - Size: 25 x 14cm (LxW). Wheel size: 6 x 2.7cm (Dia.*H). The motor power supply is 3V ~ 6V. All the parameter above is tested without load. EASY TO INSTALL - The mechanical structure is simple, with a car platform, 4 DC gear motors, flexible turning, eco-friendly chassis is stable and very easy to expand. EDUCATIONAL TOYS - Intelligent Tracing Robot car chassis, high degree of freedom, ideal for the DIY subject, science education, development of hobbies and interest, educational toys for kids. MULTIFUNCTION - Ideal for programming, home automation, RPI Raspberry DIY. You can get hands-on experience with Robotics & Can extend electronics systems like Raspberry Pi or Arduino etc. Realize functions of tracing, obstacle avoidance, distance testing, speed testing, wireless remote control. 4WD CAR CHASSIS KITS - The kit does not include any module, please purchase in need. If you have any questions or questions, please contact us. We will resolve your issue within 24 hours.