The 13 X 21 S3R Apollo is a three-blade, highly polished, maximum performance-based stainless steel right-hand rotation boat propeller and is interchangeable with the Mercury Flo-torq II hub system and built to use the Michigan Wheel XHS hub system. Has high-performance blade geometry that meets or exceeds the performance specifications. Key Features: Highly polished stainless steel finish for optimum performance Utilizes XHS Hub System and are interchangeable with Mercury s Flo- Torq II system. Fits engines for Mercury/Mariner/Mercruiser, Evinrude/Johnson, Force, OMC/Cobra Sterndrives, Yamaha, Suzuki, Honda, Nissan/Tohatsu, and Suzuki. Part Specifications: Item Number: 993146 UPC: 014984015417 Weight: 12.00 LBS Pitch: 21 Diameter: 13 Blades: Standard 3-blade Rotation: Right Hand (RH) Splines: Determined by Hub Kit Engine Types: V4 / 4 - 1/4 inch Gearcase Material: Stainless Steel Brand: Michigan Wheel Marine Condition: New Note: Hub Kit is available for purchase separately. Recommended Applications for Apollo XHS Standard 3 Blade: Inflatables, Flats Boats, Sport Boats (Duals and Singles), Bass Boats, and Aluminum Consoles. This model replaces E1-1321, E2-1321, A2-1321, A1-1321, and 14984015417. Standard 3-Blade