Use this Davis accessory to clip your fenders to rails, lifelines, side wing windows or cleats. Fender Tender II simplifies the handling and relocation of boat fenders. The Railing Lock firmly grasps rails from 7/8 to 1 (22 to 25 mm) diameter. New Lifeline Lock provides added safety. Use 1/4 to 3/8 (6 mm to 9 mm) diameter nylon line. Made of tough, sun-resistant plastic.