Mercury - Black Max Plastic Propeller 7.375" Diameter x 7" Pitch Right-Hand Rotation 3 Blades Plastic 815083A02. Overview. Sometimes, the best gear is the kind you never have to think about - it just works. The Mercury Black Max 3-Blade Plastic Propeller is one of those dependable tools you'll come to appreciate every time you start your motor. It's light, durable, and built to keep small boats running smoothly without a fuss. If you're running a portable Mercury outboard and want a prop that's