A second stage regulator and a method for using the regulator is provided. The second stage regulator has a unique design to facilitate rotation of the mouthpiece about the regulator. The mouthpiece is able to be configured and reconfigured to adapt to a plurality of uses, including commercial, emergency, military and individual use. The second stage regulator also has a plurality of openings allowing for interchangability of parts. The second stage regulator has a unique ergonomic design for optimum user configuration control. The mouthpiece may be interchanged with the exhaust opening and/or blank opening, and the exhaust may be interchanged with the mouthpiece opening and/or blank opening.