SnoBlox Ace Snow Guards 20pcs Screws and Sealant Kit for Metal and Steel Roof Panels Includes 40 galvanized #14, self-drilling screws, 2 inches long, with an attached neoprene washer. Fits most popular 36" metal panels and all standing seams! Starter points are provided for mechanically fastening. ATI lab tests show 4,849lbs strength with mechanical attachment. Free layout at www.SpacingTool.com