Here is something new and a little different than the traditional round bungey cords that we are all used to. The patented hook is super strong. A hardened metal wire form is placed in the centre of the molded poly carbonate hook making it super strong. Cord is made of rubber strands with polypropylene covering, is 18in long x 5/8in wide. Hooks are molded polycarbonate with 1in opening.