The easiest way to get your smaller robots moving! These strong, lightweight, and reliable gearboxes are priced to fit your budget! They come fully assembled with a powerful 550 Johnson motor. They are compatible with all 540 and 550 sized motors including popular R/C car motors. The output shaft is supported by dual abec 1 ball bearings and readily accepts a wheel or sprocket. An all-steel, two stage planetary gearbox increases the motor torque 36:1. Mounting holes are provided, drilled and tapped on 2 sides. Optional mouting hole configurations are avaiable.