This is an Aluminum Threaded Pinion Gear 17T for the HPI Nitro 3. FEATURES: Fine-tune the Nitro RS4-3 Two Speed Transmission (HPIC6038) with this threaded pinion gear. Color-coded for easy identification. Gold aluminum construction. It"s the perfect complement for any Nitro 3 racer! YOU WILL RECEIVE: One Gear REQUIREMENTS: HPIC6038 SPECIFICATIONS: # of Teeth: 17T Width: 12 mm jmm 10/12/02 ir/kh kr10/14/02 &