【Fits For】: RC 91T Slipper Clutch 0.6 Pitch Gear w/(19T 21T 23T 25T)Pinions & Center Drive Shaft Upgrades Part for 1/10 Granite 4X4 RTR Brushed/BOOST 2WD RTR (ARA4202XV3,ARA4202V3,ARA4103V4,ARA4103SV4),1/10 Senton 4X4 RTR Brushed/BOOST 2WD RTR (ARA4203XV3,ARA4203V3,ARA4103V4,ARA4103SV4),1/10 Vorteks BOOST 2WD RTR (ARA4105V4,ARA4105SV4),1/8 Typhon 4X4 RTR Brushed(ARA4206V3) 【19T 21T 23T 25T Pinions Gear for Choices】We provide 4 different teeth pinion gear (19T 21T 23T 25T) to make you more choice in gear ratio. 【High precision】:The Center Drive Shaft made of 6061-T6 aluminum for long-lasting durability, provides ideal replacements for your kit supplied items! 【More Durable】:The Spur Gear upgrades to more durable. Made of More Hard Steel Metal.The tough molded composite material for long-lasting durability .is with precision manufactured gear teeth for smooth, consistent performance,they works with low noise. 【Easy to Install】:great for replace the old or broken part.Increase overall performance and durability of your RC car.