The HD ISOGARD HG/HailGard Fastener is specifically designed to be used in roofing applications where ISOGARD HG/HailGard insulation or an OSB or plywood overlay is used and fastened into steel, concrete or wood decking. The HD ISOGARD HG/HailGard bugle-head design allows the head to be installed flush with the top layer of Elevate ISOGARD HG/HailGard Composite Insulation, oriented strand board (OSB), or plywood. The HD ISOGARD HG/HailGard Fastener is also an exceptional fastener for attaching ISOGARD HG/HailGard insulation when used as a substrate for roofing shingles or metal roofing.