Black Diamond Series 9-1/4"D x 9"P RH Rotation 3-Blade Aluminum Thru Hub Exhaust Propeller with 14 Tooth Spline Hub for 9.9 hp Mariner (QA2173R) by Quicksilver®. It's not just an average aluminum propeller - there is a reason the Black Diamond is the world's best-selling aftermarket propeller. No other prop on the market today provides as much performance, durability, and value as a Black Diamond aluminum propeller. It's designed to be the perfect complement to any outboard or stern drive.