The hole diameter of the 15T/17T/19T pinion gear set is:5.0mm/0.196inch, come with three 3.175mm coupler to convert 3 pinions apertures to 3.175mm/0.125inch. Work on 5mm and 3.175mm shaft motors(3660 3670 3674 4274 4268 550 540 3650 etc).
Replacement of replace for 3956, 0.8 metric pitch, compatible with 32-pitch
Suitable for traxxas slash gears, made of heavy duty hardened steel, durable.