Center Rope Tube for versatilityThe versatile Big B Fender incorporates an integral 3/4"dia. Center Rope Tube that allows end-to-end line passage. It can be hung vertically or horizontally with a single line. Horizontal hanging is useful protection against pilings, awkward docking situations, and tidal change areas. Big B fenders feature seamless construction, with molded ribs to minimize roll. Big B's are made from the highest quality marine grade vinyl with a high gloss finish. Features a football needle valve for precise air pressure regulation. Available in four diameters to fit a full range of boat sizes. 3/4"dia. center hole accepts up to 5/8"dia. rope for securing the fender Flexible, seamless marine grade vinyl construction with molded ribs. Marine grade vinyl lasts years in the sun. Four sizes, 6" x 15" to 12" x 34" White, Blue, Black, Navy, Cranberry, Hunter Green Hang it vertically or horizontally with a single line Needle-valve for easy inflation and long life The most accurate way to select the right fender for your boat is to survey your docking area to find out what fender dimensions and quantities are in use for the same size and weight of boat, and use that as a guideline Guaranteed for the life of your boat against splitting or bursting!