Sometime long ago in another thread on this same topic Iposted this out dated picture of my side rails. I redone them again as I now have a double rail frame. The side rails are made of recycled plastic approximately5/8 of an inch thick. They have served mewell, no maintenance easy to work with. Sorry to say the picture provided is the 1st set. My 2nd set are much better learnedfrom my mistakes. This product is meant tobe used in semi-trailer to protect the walls while loading pallets with forklifts so its tuff. My most recent trip wason the Grant 100 degrees days they held up great!