Barbieri Airman Black CO2 pump

One star because there is no facility for none.I hope this item was faulty, I was not going to get a replacement though. Oddly it cannot be returned as it contains compressed gas! No, it does not, it's just a valve.Anyway, it dumped the entire contents of 4 CO2 cylinders as soon as they were screwed home and I know enough physics to be wary of the freezing effect of escaping high pressure gas but still managed a mild thermal burn. My fault. However, even after applying some silicone to the cylinder neck (which did afford a seal) gently cracking the valve open, froze the bike tyre valve shut and the unit immediately overpressured. Advice; bargepoles come to mind. Amazon kindly refunded the payment and left me with the unit which is in the bin.