The ZipDock®, with its integrated self-locking mechanism, eliminates the need for knots. Its simple, adjustable and strong design keeps your boat secured to the pier with minimal effort.The easy-to-use quick release puts you out on the water in seconds. For use with recreational watercraft including pontoons, ski boats, fishing boats, jet skis, and more. Made of rugged, UV resistant polymers. Comes with braided 3/8" polypropylene rope with cleat loop. The rope floats for easy water retrieval. Fits most standard and decorative pier posts up to 4" in diameter. Strong self-locking system. Easy-to-use quick release lever.