Includes 40 galvanized #14, self-tapping screws, 2 inches long, with an attached neoprene washer. Fits most popular 36" metal panels and only requires 3 inches of flat area for mounting! Starter points are provided for mechanically fastening. ATI lab tests show 4,849lbs strength with mechanical attachment. Manufactured from virgin grade, UV stable polycarbonate to last a lifetime. SnoBlox polycarbonate clear plastic snow and ice guards are only manufactured from virgin grade, UV-stable, polycarbonate. From the originators of the polycarbonate snow guard, our products have helped prevent damage from snow and ice avalanches on sloped metal roofs since 1976. This kit is designed for screw-down metal roofs that are attached to wood purlins. Kit Includes 20 SnoBlox Ace Snow Stops, 2 tubes of NovaFlex Neutral Cure Clear Sealant, and 40 self-tapping #14 screws with an attached neoprene washer that measures 2 inches long. Verify the thickness of the insulation under the panel, if any, to ensure the provided 2-inch screws fully engage in the purlin. The Sealant is safe for use on Kynar and Galvalume panels with a service Temp of -40F – 400F. Application temperature is between 0F – 120F. Instructions for installation can be seen in pictures. Placement of snow guards in just isolated areas such as chimneys, doorways, vents, and partial roof sections is NOT recommended. A spacing recommendation and layout tool for snow guards is available at http://www.spacingtool.com