54T motor main gear comes with 16T/18T/20T/21T and 3.175mm coupler.Four is 5mm, Using the coupler can convert Four pinion apertures to 3.175mm.so this product for motors with 5mm or 3.175mm shaft diameter.3660 3670 3674 4274 4268 550 540 3650 etc series motors.54T main gear replace 3956. 0.8 metric pitch; compatible with 32-pitch; pinion sinner diameter: 5.0mm/0.196inch; main motor gear dia.: 45mm/1.77inch;inner diameter: 11.9mm/0,47inch. compatible with Slash 4WD/2WD/VXL /Stampede VXL / 1/10 Summit/Trxxas 1/10 E-/-/Jato/ VXL/Summit/-. All metal internal gears for strength.Made of heavy duty hardened steel, long span. The speed depends on ration. We provide four different teeth pinion gear to make you more choice in gear ration.<br><br>Colour: black Material: metal<br><br>Package Contents: 1 * 54T Gear 1 * 16T Pinion 1 * 18T Pinion 1 * 20T Pinion 1 * 21T Pinion 4 * Screws<br><br>Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.