Steel Machined Underdrive Axle Differential Helical Gears Ring Pinion Set for 1/18 RC Crawler TRX4M Upgrade Hardened steel, CNC machined Helical gears designed for better transmission Fits 1/18 RC Crawler TRX4M Specifications: Item: Axle Diff Gears Compatibility: for TRX4M Material: Steel Gear ratio: 24/12=2:1(Same as Stock) Weight: 6g Color: Black What’s Included: 2pcs Ring Gear 2pcs Pinion Gear