for 1/7 Arrma Big Rock Mojave Felony Infraction Limitless 6S 1/8 Kraton Tailon Outcast Notorious Typhon 6S Pinion Upgrade Parts
The pinion gear shaft diameter or bore is 5mm, make sure your RC motor shaft have the same diameter.
The RC upgrades pinion gear set are made of quality hardened steel, durable and reusable, enjoy your happy RC racing time.
Mod1 is the pitch of each tooth on the pinion gear and the 16T 17T 18T 19T is the number of teeth on the pinion gear. You have to make sure your spur gear and pinion gear have the same pitch, or the teeth won't mesh.
Comes with set screws for each pinion gear, the pinion gear combo set also included a hex key, easy to install.