the disclosure embraces a connecting tee for use with a contained air supply to enable two or more individuals to draw air from the supply and includes a chamber having one passage connected to a source of air , a first passageway with a one - way check valve for supplying air to a first user and a second passageway which is provided with a pair of one way check valves ; the first valve of the second passage permits air flow out of the connector from the source but prevents inflow of external air ; the second check valve of the second passageway is normally in a closed position but is manually opened where a second user must establish communication with the source of air carried by the first user .