These products are so strong you can drive an 18-wheeler semi-trailer over them and they won't burst! Guaranteed. They are ribbed - so they resist rolling alongside your boat. They use premium marine grade heavy wall vinyl for rugged durability. They are soft to prevent scratching to your precious hull/s, have UV protection and are specially treated to prevent rotting, developing mould or mildew. Each fender has a large eyelet at each end. (In the USA and Canada, fenders are generally tied festoon-like, rather than vertically, further preventing roll). 4 sizes are available, all white in colour. Ribbed Boat Fenders - TOUGH Length : 400.0mm Diameter : 115.0mm