The bail-out breathing valve is demand-controlled, which means that gas is only supplied when inhaling. The bail-out breathing valve is balanced to ensure low breathing resistance regardless of any variations in the supply pressure. Balancing means that the valve mechanism is designed to ensure any variations in supply pressure do not affect the sealing and control forces in the valve. The valve works with the same performance regardless of variations in supply pressure. The bail-out breathing valve also has a safety pressure function that allows for a secondary pressure that exceeds about 20 bar (2 MPa) to open the valve and release the overpressure.

The bail-out breathing valve in the outlet to the mouthpiece is fitted with a non-return valve that prevents water from penetrating through – and preventing the risk of freezing in open position (free flow of gas).

When diving, the bail-out breathing valve is attached by means of a bayonet coupling directly to the switch-over valve on the face mask.