Turning Point Express Mach4 - Right Hand - Stainless Steel Propeller - EX-1513-4 - 4-Blade - 15.3" x 13 Pitch [31501330]Express Mach4 Right Hand Stainless Steel Propeller EX 1513 4 4 Blade 15. 3" x 13 Pitch The Prop that put the "four" in Perfourmance! Turning Point's Four Blade revolutionized the aluminum propeller market when introduced over 6 years ago. No one had ever produced an aluminum 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: two blades utilize