The Pololu 3740 / 3741 /3739 3pi+ 32U4 Robot Kit is a complete, high-performance mobile platform based on the Arduino-compatible ATmega32U4 MCU, and this kit contains all the parts you need to build the Standard Edition version, Turtle Edition, Hyper Edition, including a pair of 30:1 MP, 75:1 LP, 15:1 HPCB 6V Micro Metal Gearmotors. The many features of the 3pi+ include dual quadrature encoders for closed-loop speed or position control, line sensors, front bump sensors, and a full IMU (3-axis accelerometer, magnetometer, and gyro), all packed into a robot that can fit within the palm of your hand. This product is a kit; assembly (including soldering) is required. The 3pi+ features two H-bridge motor drivers and a variety of integrated sensors, including a pair of quadrature encoders for closed-loop motor control, a complete inertial measurement unit (3-axis accelerometer, gyro, and magnetometer), five downward-facing reflectance sensors for line-following or edge-detection, and left and right bump sensors along the front face of the robot. Three on-board pushbuttons offer a convenient interface for user input, and an LCD, buzzer, and indicator LEDs allow the robot to provide feedback.