Secure-A-Tach Fastener is an easy-to-use loop fastener to permanently close them. These polypropylene fasteners reduce handling time with double-barreled locking head & an arrow tip that can be applied through either end of the barrel. They are easy to use. Simply insert the tail of the fastener into the head for a secure lock without tools or needles. Tensile strength is 12 lb. Perfect solution for tagging hard goods, they are fast, cost-effective & secure. Avery Dennison's proprietary stretching technology produces stronger, more flexible fasteners. Weatherproof loop fasteners are great for using on bags, luggage, sunglasses & other items where tagging guns cannot be used.