Since the Zeagle RaZor is both a Regulator and a Valve, a means has to be provided to fill the cylinder that the RaZor is screwed into. Most RaZors come with a filling adapter that provides either a connection point for a standard Scuba Valve Filling Whip or a connection to a standard tank valve. A cap is unscrewed from the Filling Probe on the RaZor and the filling adapter is connected in its place. The RaZor comes equipped with a Burst Disc rated at 3000 PSI working pressure.