GoolRC 48DP 31T 32T 33T 34T 35T Pinion Motor Gear Combo Set for 1/10 RC Car Brushed Brushless Motor Suitable shaft diameter: 3.175mm A m3 set screw (12.9 level) has been added to each pinion gear. Originally Aluminum 7075 Hard anodized on the gear surface A m3 set screw (12.9 level) has been added to each pinion gear