Save these from the scrap bin! I'm moving and don't wanna take em with me. Unless noted, $13 each untested, unwarranted. I believe these will work but I don't have the right bottles (argon, etc) to use with em. A couple are CO2 as noted. Do note that these are industrial regulators so they're heavy. Buyer to pay actual shipping - when inquiring indicate which regulator number you're interested in, your zip code, and whether the ship to address is business or residential. This'll take a few posts to get all the pictures up...