Mercury Enertia Stainless Steel Propellers offer large blade diameter and patented high output geometry to produce outstanding speed with less effort. Mercury Enertia Propellers improve acceleration and top speed on larger high horsepower boats. For Stern Drives and Outboards 150 hp and up, especially for offshore fishing, bay, and sport boats. Mercury Enertia Propellers use the Flo Torque II Hub System.