Product Description Specifications Documentation Pinion for P7 gearboxes with a first stage of 4:1 and a motor with a 3.2mm shaft such as a RS-5nn sized motor (RS-540, RS-545, RS-550, RS-555, etc)Pinion is an interference/press fit. For P7 Gearbox 1st Stage: 4:1 Bore: 3.2mm Max Bore: 0.315in (8mm) Length: 0.47in Installation: Interference (press) fit Number Teeth: 16 Gear Specs: 0.7Mod, 20PA Gear Material: Cold Rolled Steel Click arrow in center of image to load and interact with it Your browser does not support iframes.