Davis Fender Tender II (Pair) 
Fender Tender II
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.
Quick Guide (pdf)