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: BF 35 and BF 45 (1991-94), BF 40, 50, and 50A (1995 and Newer), BF 60 (2010 and Newer); 13 Tooth Spline. 3-1/4" Gearcase.