Evolution Shaft Razor shaft cutter. 316 stainless steel. For 1.38" shaft. Keeps your propeller and shaft free from fouling ropes and submerged debris. The Shaft Razor cutter is a machined circular blade with two sharp serrated cutting edges. It is machined to the shaft diameter and held in place with set screws. Once installed the cutter rotates with the shaft and gently cuts anything that becomes entangled on the shaft/propeller.