A trapeze shock cord is an absolute necessity because it keeps the trapeze system in place and ready for hook-up. One hook connects to either the thimble on the trapeze wire or the adjustment line, then runs under the tramp and connects to the other side in the same location. Shock cord comes with one plastic carbine hook installed; the other hook is installed after lacing shock cord through trampoline grommets. Cord is 1/4" diameter by 12′. Each.