Features: Adapt to upgrading and refitting of Remote Control car. All metal internal gears with high strength and long service life. The steel gear set is suitable for FCX24, FCX18 remote control models. Hardened steel to increase strength and weight of the axles. Transform your remote controlled adventure with precision cut gears that promise to deliver the torque and longevity needed for competitive game or leisure play. Specifications: Component: 45 # Hardened Alloy Steel Type: 20T/24T Size of 20T: Approx. 7.8x12mm/0.3x0.47inch;12.4x16.3mm/0.50x0.64inch. Size of 24T: Approx.7.8x11.3mm/0.3x0.44inch;15.8x16.3mm/0.62x0.64inch. Package Includes: 1 Set Gears note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind before you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color of the item.