The Zumo robot for Arduino is an Arduino-controllable tracked robot platform that is less than 10 cm × 10 cm—small enough to qualify for Mini Sumo. It includes two micro metal gearmotors coupled to a pair of silicone tracks, a stainless steel bulldozer-style blade, an array of six infrared reflectance sensors for line following or edge detection, a buzzer for simple sounds and music, and a 3-axis accelerometer, magnetometer, and gyro for detecting impacts and tracking orientation. Just add 4 AA batteries and an Arduino (or compatible controller) and you are ready to push! No soldering or assembly is required.
For more information, visit Pololu's official Zumo Robot Listing