5-Pack Black Steel Metal 5mm Pinion Motor Gear 17T 18T 19T 20T 21T,

Remove the old pinion gear from your RC car. Ensure the new gear (17T, 18T, 19T, 20T, or 21T) is compatible with your RC car's spur gear and motor shaft. Install the new gear onto the motor shaft. Secure the gear with the provided grub screws.