I stumbled across this a while back when I found myself intrigued by SodaStream. It's a 5lb cylinder with a reg set at 60 psi. The guy says he's tested it to 90.
edit - he also mentions that he picked up the cap and quick-release for 6 bucks shipped Evilbay. Not the same as pictured above.
Last edited by kevmo911; 02-08-2013 at 03:12 AM.