I couldn't find the little certificate the first set I sent back. I called them and told the girl on the phone that I had a receipt from Summit if that would work and she said just send them on in with the return shipping money, bout $20 IIRC, had zero problems. I use their camlock version with the double crotch strap and I really like them. The first set I had was the older black webbing. The silver is softer and easier to use.
Curtis