32DP Pinion Gear Set made from 7075 Aluminum. 3.175 bore to fit our 540 RC motors. Pairs perfectly with spur gears for the Skeeride RC Snowmobile. Includes 5 pinion gears with 12, 13, 14, 15 and 16 teeth and 5 set screws. When installing we recommend starting with lower teeth amounts and then increasing if/when you need more speed.