The RBX Interchangeable Hub seats to the propeller hub cavity in order to eliminate hub chatter and vibration while preventing spinning within the propeller. It features a one-piece rubber construction with anodized aluminum splines - no plastics to deteriorate. Hubs offer 10° deflection to reduce banging when shifting gears or hitting a submerged object. All RBX hubs are reusable if the propeller is damaged. Designed for use with the following: Nissan/Tohatsu 50 HP (50C only) 1987-91, 55 HP (1981-88), 60A (1986-99), 70A and 70B (1981-95); 13 tooth spline with 3-1/4" Gearcase.