Micro Metal Gearmotor 50:1

This motor has a long (0.365" or 9.27 mm), D-shaped metal output shaft that matches the Pololu wheel 42x19mm and 32x7mm. The brass faceplate has two mounting holes threaded for M1.6 screws (1.6 mm diameter, 0.35 mm thread pitch), or you can use the mounting bracket or extended mounting bracket, which are specifically designed to securely mount the gearmotor while enclosing the exposed gears. We recommend the extended mounting bracket for wheels with recessed hubs, such as the wheel 42×19 mm.