Durable Rubber Roller: Made from strong, thermal plastic rubber to meet boating needs and to ensure long-lasting performance Tool for Bow Protection: Prevent bow-to-bow stand contact and help center your boat with this sturdy assembly Accessory Fit for Boats: Designed with a 5-1/2" diameter, this 8" wide rubber roller is perfect for boat trailers and fishing boats; fits 4” wide center roller brackets Easy Roller Installation: Install on your boat trailer to help center the boat and prevent bow-to-bow stand contacts; includes necessary installation accessories CE Smith Marine Accessories: CE Smith is committed to providing quality trailer and fishing products with responsive customer service