7431 permanent roof anchor is constructed using rugged alloy steel D-rings connected by a stainless steel strap. It is easily installed by forming it to conform to any roof peak and driving 10 16d nails through the holes and into the truss. Designed to be covered with ridge caps and left behind for future use. Excellent for maintenance and homeowner applications. Double D-ring; Permanent Roof Anchor with Stainless Steel Body; Fastens Under Shingles, Leaving D-rings Exposed for Attachment; 17" Including D-rings with 12" Nailing Surface. Conforms to roof peaks of 1/12 or greater.