CNC 3614350 3 Blade Magnalium 7075 propeller. Machine-cut to high tolerances, this prop is ready to use right out of the box. The Magnalium 7075 alloy makes this material upwards of 30% stronger than standard 7075 aluminum. Left-hand rotation. These spin counterclockwise when viewed from the back of the boat. Fits 1/8"(.125" 3.17mm) smooth-bore propeller shafts.