These Jump cup strips are made of tough, flexible, UV-stabilized polypropylene plastic. The sun will not hurt them and they will stay flexible even at sub-zero temperatures. The jump cup strips are very easy to install, just clip them onto your 1" or 11⁄4" PVC jumps and you are ready to go! Screws are provided if you want to permanently attach them. These jump cup strips will work on PVC pipe, metal frame and wooden jumps.