Make towing your boat to your next adventure a breeze with the SeaSense Poly Vinyl 10 in Trailer Keel Roller. This keel roller allows your boat to roll smoothly on and off your trailer for convenient towing. The rubber, nonmarring poly vinyl and polyurethane construction encourages durability and helps prevent marking your boat, while the free spin design reduces drag when launching your boat for a smooth performance. 5/8-inch shaft. 10-inch size.