Feature: 1. Compatible with Various Models: This gear set is suitable for ARRMA Big Rock 1/10, for Senton, for Vorteks, for Typhon 3S 1/8, for Kraton, for Outcast 4S and other remote controlled cars. 2. Precise Fit: The 57T slipper gear snugly fits into the original mounting holes of the RC cars, ensuring accurate shape and size, and minimizing occurrences of jamming during use. 3. High Strength Steel Construction: Made of hardened steel for increased durability, capable of handling 4S batteries without slipping, and equipped with an aluminum alloy output shaft. 4. 4 Motor Gears: Available in two configurations with different motor shaft diameters, 3.175mm (20T and 21T) and 5mm (20T and 21T), the RC motor gears are suitable for both brushless and brushed RC models. 5. Superior Processing Quality: Compared to other gears, this slipper gear set features excellent machining that reduces roughness and noise, resulting in smoother and steady gear rolling. Specification: Item Type: RC Gear Set Material: Steel, Aluminum Alloy Gear Module: 0.8mod Gearbox Gear Teeth: 57T Motor Gear with 3.175mm Bore Teeth: 20T, 21T Each Motor Gear with 5mm Bore Teeth: 20T, 21T Each Application: for ARRMA Big Rock 1/10, for Senton, for Vorteks, for Typhon 3S 1/8, for Kraton, for Outcast 4S RC Cars. Package List: 1 x Gearbox Gear 4 x Motor Gear 4 x Machine Screws 2 x Right Angle Wrench 1 x Output Shaft