Rover 5 is a new breed of tracked robot chassis designed specifically for students and hobbyist. Unlike conventional tracked chassis's the clearance can be adjusted by rotating the gearboxes in 5-degree increments. "Stretchy" rubber treads maintain tension as the clearance is raised. Inside of the chassis are 4 noise suppression coils at the bottom and a battery holder that accepts 6x AA batteries (not included). It is recommended to use NiMh batteries as they last longer and have a higher current output than Alkaline batteries. Each gearbox has an 87:1 ratio and includes an optical quadrature encoder that gives 1000 pulses over 3 revolutions of the output shaft. The chassis can be upgraded to include four motors and encoders making it ideal for mecanum wheels. Fully assembled and ready to use however please note that a robot encoder and sensors are required for building a complete robot. Specifications: Motor rated voltage: 7.2V. Motor stall current: 2.5A. Output shaft stall torque: 10Kg/cm. Gearbox ratio: 86.8:1. Encoder type: Quadrature Encoder resolution: 1000 state changes per 3 wheel rotations. Speed: 1Km/hr. Four motors, Four encoders. Encoder interface: Red = +5V, Black = 0V, Yellow and White = Quadrature encoder outputs. Weighs 2.5 pounds without batteries.