This motor kit includes high quality metal gear with matched Pololu wheel 42x19mm and a mounting base bracket specifically designed to securely mount the gearmotor.The motor has a long (0.365" or 9.27 mm), D-shaped metal output shaft that matches the Pololu wheel 42x19mm. The brass faceplate has two mounting holes threaded for M1.6 screws (1.6 mm diameter, 0.35 mm thread pitch) FeaturesGear ratio: 100:1