This is an expansion board for the core controller of dual self-balance car, which is fully compatible with Arduino UNO. There are some module interfaces on the board, such as motor driver module, gyro module, ultrasound module, Bluetooth/ WiFi module. It allows you to connect two motors on this board for there are two motor interfaces. On the back it has interface of Arduino UNO, which make it easy for you to DIY your robot with Arduino UNO.