Designed for high-power, fast-bottom boats, these Michigan Wheel propellers are cupped for extra speed with minimum cavitation. Cast of NiBrAl, a special blend of nickel, bronze, and aluminum, these outstanding props will absorb higher horsepower without deflection or distortion. Michigan Wheel's ski boat propellers provide consistent response to your throttle commands. Vendor Part Number: 310661 Absorbs higher horsepower without deflection Ski boat propellers provide consistent response | Dyna-Jet Cupped 3-Blade Prop, 1" SAE / Nibral, 13 dia x 13, LH