This is the 18 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 Number of teeth laser etched on shaft 18 Tooth Pinion Gear, M5 Set Screw Installing on motor shaft and securing with set screw Number of Teeth: 18 Gear Pitch: MOD1 Hole Diameter (Bore): 5mm jxs 10/18/11 ir/jxs &