The invention relates to a device for supplying breathing gas to a user, the device (10) comprising: a mask (12) having a breathing opening (22)； and a bag (14) having a bag opening (23) that is connected to the breathing opening (22) in fluid communication, wherein the device (10) further comprises an adjustable exhalation valve (18), wherein the adjustable exhalation valve (18) is in fluid communication with the bag (14). Thus, the invention provides an improved device for supplying breathing gas to a user providing protection against hyperventilation, toxic gases and smoke.
