The 3M™ Flame Resistant Hook Fastener SJ3519FR is one part of a two-part fastener solution designed to provide great durability for thousands of closures. With its flame-resistant, rubber-based, pressure-sensitive adhesive backing, this fastener allows for easy and convenient attachment to a variety of substrates, including plastics. To ensure stability and flatness, both the hook and the corresponding loop are preshrunk.The 3M Flame Resistant Hook Fastener SJ3519FR is a flame resistant, rubber based hook fastener with a 3 mil (0.08 mm) polyethylene film liner featuring red 3M print. It is an attachment alternative to a wide variety of closures, including zippers, screws, snaps, hooks and more. This nylon fastener is covered with flexible J shaped hooks, about 300 hooks per square inch (46 hooks/square cm.), which protrude up from a woven backing. This fastener should be paired with 3M Flame Resistant Loop Fastener SJ3518FR. To ensure stability and flatness, both the hook and the corresponding loop are preshrunk.