This is the Robison Racing Hardened Steel 1.0 Mod 46T Spur Gear for use on the HPI 1/8 Savage X 4.6 RTR Nitro Truck FEATURES: Hardened steel construction INCLUDES: One 46T 1.0 Mod Spur Gear RRP Decals REQUIRES: Installation on the vehicle SPECS: Outer Diameter: 50mm (2") Inner Diameter: 8mm (0.31") Width: 9mm (0.35") Teeth: 46 cnh 4/10/09