The 3M™ Hook Fastener SJ3402 is one part of a two-part fastener solution designed to provide great durability for thousands of closures. This non-adhesive fastener is most commonly sewn, but can be attached with a variety of hot melt or liquid adhesives. This fastener allows for easy and convenient attachment to a variety of substrates. 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, with about 300 hooks per square inch (46 hooks per square cm) that protrude up from a woven backing. Commonly paired with 3M™ Loop Fastener SJ3401, 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.The 3M Hook Fastener SJ3402 is a general purpose hook fastener that features no adhesive or liner. 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 SJ3401, 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.