CNC round ear style aluminum props.Size options from 42mm to 72mm diameter, see picture two for specs. Machine cut to high tolerances makes this prop 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 counter clockwise when looking at them from the back of the boat. Shaft sizes42 to 50mm props fit a 3/16"(.187" 4.76mm) propeller shaft.72mm prop fits a 1/4"(.250 6.375mm) propeller shaft.Includes:(1) Prop