If you're looking at this then you've probably stripped the original Pinion Gear (and/or Spur Gear) on your new Traxxas, and are looking for upgrade parts. The metal quality of these gears that comes from factory with the car are not great, so even if you haven't stripped them yet, I'd recommend buying these upgraded versions. This pinion gear matched with the [XO050TS-BK] 'GPM Steel 50T 1Mod Spur Gear' (also sold on this site) WILL fix the stripped tooth issue. Just make sure you use loctite 243 (the blue one) and put a dap in the hole of the pinion gear before screwing in the grub screw to hold it in place, and wipe off excess loctite if any is squeezed out the end. It is recommended to wait 24 hours for the loctite to cure to ensure the pinion gear won't slip on hard accelerations/stops. I applied mine and went driving straight away with no issues, however. And as always, ensure your gear mesh isn't too tight after installing these gears, prior to driving.