This is a HPI 32 tooth (0.6M) Pinion Gear. Precision made Stamped for easy identification One 32T 0.6 pitch Pinion Gear One 3x3mm set screw Installation Length: .41" (10.5mm) Inside Diameter: 1/8" 3.17mm Outside Diameter: .64" (16.19mm) Not compatible with 48 and 64 pitch spur gears mm 5/07/08 ir/mlm &