The Sherwood SR2 is one of the world's best breathing regulators. It is a Dry,Environmentally Sealed Piston 1st Stage. And has a compact, lightweight 2ndstage. The One-Touch performance adjustment maintains the flow of air andventuri with a single knob adjustment. The SMART Demand Lever relieves theload on the Low Pressure Seat when not under pressure. The Dry 1st stage keepsall contaminants out. Five Low Pressure Ports on a 360 degree swivel. Two HighPressure Ports.