Features 1、High Hardness: RC pinion gear set is made of high accuracy Cr Mo alloy steel with heat treatment process, which has super hardness and wear resistance, corrosion resistance and long service life. 2、Stable Working: Compared with other gears, RC gear has good machinability, low roughness and low noise, making them roll smoothly and work smoothly. 3、Different Teeth: Motor gear set provides five pinion gears with different number of teeth, 38T, 39T, 40T, 41T, 42T, allowing you to have more choices in gear ratios, making the RC car perform better. 4、Exquisite Workmanship: RC motor pinion gear adopts accuracy machining to make the gear roll smoothly, and comes with fixing screw holes for easy installation and simple operation. 5、Ideal Replacement: The RC motor gear has an anti rust finish and is an ideal replacement for old or damaged originals, suitable for 1/10 RC model car 3.175mm axle motors. Item Type: RC Pinion Motor Gear Product Type: RC Accessory Material: Cr Mo Alloy Steel Colour: Black Number of Teeth: 38T, 39T, 40T, 41T, 42T Gear Pitch: 48DP 0.53M Center Aperture: Approx. 3.175mm / 0.13in 38T Size: Approx. 21.2 x 11mm / 0.83 x 0.43in 39T Size: Approx. 21.4 x 11mm / 0.84 x 0.43in 40T Size: Approx. 22.2 x 11mm / 0.87 x 0.43in 41T Size: Approx. 22.7 x 11mm / 0.89 x 0.43in 42T Size: Approx. 23.2 x 11mm / 0.91 x 0.43in Scope of Application: For 1/10 RC Remote Control Model Car Motor 3.175mm Axle. Package List 5 x RC Pinion Motor Gear 5 x Set Screw 1 x Wrench