This is the optional 16 Tooth Pinion Gear for the DuraTrax DX450 Motorcycle DTXD02**. FEATURES: Constructed of steel Provides slightly slower acceleration but faster top speed than stock 13 tooth pinion gear YOU WILL RECEIVE: 16 Tooth Pinion Gear with set screw REQUIREMENTS: Attaching to motor shaft jxs 01/25/10 ir/jxs &