A breathing gas dispenser with selectable output flow rates. The dispenser includes a vessel containing a supply of breathable gas at storage pressure. The vessel is in fluid communication with a regulator assembly capable of reducing the pressure of the gas to a delivery pressure in a chamber. A plate is disposed in the chamber. The plate has a plurality of openings defined therein. The openings are disposed in pairs including a first opening and a second opening. The first or second opening or both may contain an orifice housing with a precision metering orifice defined therein. A flow selector is capable of causing the plate to rotate such that each of the pairs of openings are sequentially brought into registry with the outlet such that a user can select an output flow rate.