Mercury - Quicksilver Black Diamond 3-Blade Aluminum Propeller 12.5" Diameter x 23" Pitch Right-Hand Rotation 3-Blade Aluminum High-Gloss Black Finish QA2042X. Overview.. There's something deeply satisfying about a prop that just feels right - smooth, balanced, and responsive from the first touch of the throttle. The Quicksilver Black Diamond 12.5" x 23" Pitch Propeller (QA2042X) is one of those dependable workhorses you can trust season after season. It doesn't try to impress with flash - it si