3M Hook Fastener SJ3526N is one part of a two-part fastener solution designed to provide great durability for thousands of closures. With its high performance rubber-based pressure sensitive adhesive backing, this fastener allows for easy and convenient attachment to a variety of substrates, including plastics. 3M Hook Fastener SJ3526N is our best in class rubber-based hook fastener with a 3 mil (0.08mm) 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 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. Commonly paired with 3M Loop Fastener SJ3527N, this hook fastener can also engage with other 3M Loop Fasteners. To ensure stability and flatness, both the hook and the corresponding loop are preshrunk.