Turning Point - Express Mach4 Stainless Steel Propeller - Right Hand - 4-Blade - 15" x 15 Pitch - EX-1515-4 - 31501532Turning Point Express Mach4 Stainless Steel Propeller Right Hand 4 Blade 15" x 15 Pitch EX 1515 4 31501532 The Prop that put the "four" in Perfourmance! Turning Point's Four Blade revolutionized the propeller market when it was introduced. No one had ever produced a propeller with two different blade shapes (they call it Dual Geometry) for 90 300+hp applications. This prop is uniquely engineered with two blade geometries: (diagram label 2)two blades