Novak 5120 Mod 1 5mm Steel Pinion (3-Pack), 9/10/11 T FEATURES: Hardened steel construction Recommended when converting 1/8-scale nitro off-road vehicles for brushless electric use Fits Mod 1 spur gears c INCLUDES: One each 9, 10 and 11 tooth Mod 1 Steel Pinion Gears and three 4x4mm set screws REQUIRES: Installing on motor shaft and tightening set screw