Mercury - Pro Max Racing Propeller - 4-Blade - 150 to 400 HP - 14.5 Dia. - 24 Pitch - 48-8M0079692 The Pro Finished Pro Max has a polished appearance with durable leading edges, robust blade thickness, tuned cup height, and zero balanced. Lab Finished also has a polished appearance, crisp leading-edge, thinned blades, tuned cup height, and zero balanced (expect to gain 150 RPM over Pro Finished, pitch for pitch). The Pro Max propeller fits 150 t0 400 HP Mercury outboard models only Applicable for performance bass boats, 19 to 22 foot single outboard performance vee bottoms, and tunnel boats.