This is the optional Robinson Racing Hardened Aluminum Diff Gear for the Associated RC10 GT2 RS RTR (ASCC7092). FEATURES: Hardened aluminum construction Replaces stock plastic gear YOU WILL RECEIVE: One Hardened Aluminum Diff Gear REQUIREMENTS: Installation on the vehicle SPECIFICATIONS: Outer Diameter: 28.5mm (1") Inner Diameter: 7.4mm (0.29") Width: 8.9mm (0.35") cnh 4/2/09 ir/jxs &