CE Smith Bow Bell Trailer Roller AssemblyCE Smith Bow Bell is constructed of thermal plasticized rubber making it durable. Helping you get your boat on the trailer on the first go and preventing damage from boat to trailer contact makes this the perfect item for any boater.29332 Specifications:6″ Wide1/2″ ShaftFits 3″ wide center roller bracketBlack TPR4-1/2″ Diameter29333 Specifications:8″ Wide1/2″ ShaftFits 4″ wide center roller bracketBlack TPR5-1/2″ Diameter