This is the 28 Tooth M5 Pinion Gear from Tekno RC. Ideal for 1/8 scale and other MOD1 pinion applications Constructed of CNC machined steel, lightened and hardened for durability Standard length shank Number of teeth laser etched on shaft 28 Tooth Pinion Gear, M5 Set Screw Installing on motor shaft and securing with set screw Number of Teeth: 28 Gear Pitch: MOD1 Hole Diameter (Bore): 5mm jxs 10/18/11 ir/jxs &