Tekno RC 4175 15t M5 Pinion Gear (Mod1/5mm Bore/M5 Set Screw) Sized from 11t all the way to 30t, you are sure to find the right gear ratio for racing or those insane speed runs. The M5 set screw ensures that your gear will stay put during operation and ensure you won't strip it out when you need to remove it. The gears are CNC machined, lightened, then hardened for incredible durability. A laser etched size identification finishes it off.Features: Massive M5 set screw gri