Developed with your boating needs and safety in mind, Fendergrip will help you set up, adjust, and use your fenders more effectively. The push-button feature of the Fendergrip provides fender height adjustment in seconds with a positive lock to hold the line in place once it is released. For use with 3/8" to 1/2" lines and rails up to 1" diameter. Made in USA. Backed with a limited lifetime warranty.