The common industrial/beverage Co2 cylinder in the states has a CGA (Compressed Gas Association) 320 fitting. The regulator with the extension cord looks like a heated regulator, http://www.google.com/search?hl=en&biw=1429&bih=822&gbv=2&tbm=isch&sa=1&q=heated+co2+regulator&oq=heated+co2+regulator&aq=f&aqi=&aql=&gs_sm=e&gs_upl=152560l167639l0l22l21l1l11l1l0l246l1390l1.7.1l9 is a google image search for heated Co2 regulators.
They were originally designed for mig welding applications. Co2 is in a liquid state in the cylinder, the liquid has to change to gas in the head space provided the cylinder. If your drawing gas out of the cylinder at a high rate such as welding you can frost/freeze the regulator.
Regulator Nut, Nipple and gasket
Co2 Cylinder Valve