Overdrive Underdrive Differential Axle Steel Helical Gears Ring Pinion Set for 1/10 RC Crawler TRX4 TRX6 Upgrade Parts Hardened steel, CNC machined 10T/35T Gears decrease speed approx 9% 12T/33T Gears increase speed approx 9% 11T/34T Gears do not increase speed, same as stock gears Helical gears designed for better transmission Fits 1/10 RC Crawler TRX4 and TRX6 Specifications: Item: Axle Diff Gears Compatibility: for TRX4/TRX6 Material: Steel Overdrive Gears: 12T/33T Underdrive Gears: 10T/35T Stock Gears: 11T/34T Weight: 21g Color: Black Poly bag package What's Included: 1 * Ring Gear 1 * Pinion Gear