Preece Precision Solid Brass One Piece Compact CGA 320 Carbon Dioxide Co2 Tank to CGA 580 Nitrogen Argon Regulator Adaptor. Simply attaches to the CGA320 Valve Outlet with a no leak permanent washer, and CGA580 seals to a permanent oring inside. Snug it up with a 1/4 turn and you are ready to run your Inert Gas (ARGON/NITROGEN/HELIUM) regulator off your CGA320 Co2 tank.