The Solas Rubex Hub Kit let you easily switch out the hub on your prop assembly. Rubber construction won't deteriorate like plastic. Anodized-aluminum splines provide long-lasting durability. Seats well so it won't chatter, and it delivers 10 of deflection to reduce banging while changing gears. Easily switch out hub on prop assembly Rubber: won't degrade like plastic Anodized-aluminum splines 10 of deflection to reduce banging For more information, view the Solas Rubex Hub Kit Product Size Guide