The original patented Clear Snow Guards for metal roofs since 1976. Fits most exposed fastener metal panels and can straddle minor ribs! Pre-drilled screw holes for quick installation! ATI lab tests show 1,800 lbs. strength with mechanical attachment. Includes 40, two inch self-tapping neoprene washer screws, 1 tube of sealant and cleaning wipes. Snow Guards are rooftop devices for glossy coated metal roofs that minimize the dangerous movement of snow and ice. While adding beauty and function, our clear polycarbonate snow guards help prevent damage from a metal roof snow avalanche while remaining practically invisible. This kit is designed for screw down metal roofs that are attached to wood purlins. Kit Includes: 20 Original Clear Polycarbonate Snojax I Snow Stops, 2 tubes of NovaFlex Neutral Cure Clear Sealant and 40 self-tapping #14 screws with an attached neoprene washer that measure 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.