THB-4 hooks fit 1/4" shock cord.  These Molded Shock Cord Fasteners are rust and corrosion proof, and since the entire unit is molded, the traditional metal crimp ring is eliminated. They securely grip shock cords by means of a patented fastening mechanism, and the slip ring conceals the end of the shock cord, giving it a clean finished appearance.  Sold by the each or bag of 100.