The Ridgeline support pole system is easy to install. It creates a ridge in the boat cover that prevents water buildup or sagging in your boat cover. The vinyl tubing at wear points protects the boat's finish. The boat cover support system includes a telescoping pole that adjusts from 20" to 48", a 1" nylon webbing strap to form a ridge under the cover to prevent standing water, and 2 stainless steel, rust resistant hooks that attach to the transom. This fits boats up to 28' long.