Elastic Straps (bungees)never seem to be the length you want so i use cut from a reel at B&Q about 5mm in dia elastic which can be used in any length. The clever bit is the termination to make it look neat and tidy so I cut a very short length of 10mm copper pipe squash it slightly so it becomes an oval and then you can get the elastic down inside and back out to make a loop which can be hooked on to anythink you like or a complete loop of any length can be made . Once you are happy with length and the stretch bit squash the copper in a vice and or centre or pin punch the copper and that will stop it moving. And it comes in bigger Dia. Mick