Royal Wire's double wire hooks are made out of 5/16" diameter carbon steel wire and then zinc plated or powder coated to guard against rust and corrosion. Recommended usage to hang: Bridles, Halters, Lead Ropes, Lunge Lines, Coats...anything you can come up with! All double wire hooks fit over a standard "2x4". This hook is 15" long. Hooks are now sold individually.