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: 25 HP Bigfoot (1999-05), 30 HP Bigfoot (2010 and Newer), 30HP (2 and 4-Stroke) (1994-05), 30 HP (Sea Pro/Marathon) (1994 and Newer), 35 HP (1984-89), 402 and 500 Models (1974-84), 40 - 50 HP (2 and 4-Stroke,Not Bigfoot) (1997 and Newer), 45 HP (1986-1989), 48 HP (Mariner) (All Years), 55 HP (Sea Pro/Marathon) (1995 and Newer), 60 HP (Mariner) (1976), 60 HP (2 and 4-Stroke, Not Bigfoot or Sea Pro/Marathon) (1978 and Newer), 65 HP (Includes Model 650) (1972-1976), 70 HP (Includes Model 700) thru (1983), 80 HP (Mariner) (1977); 13 Tooth spline, 3-1/4" Gearcase.