The Sundström SR 200 Airline is a breathing apparatus that is supplied with a continuous flow of air and is designed for connection to a compressed air supply. The unique feature of the SR 200 Airline is the scope it provides for filter back up. The breathing hose can be released from both the facepiece and the control valve. The equipment can then be used as a filtering device. The SR 200 Airline can be used as an alternative to filtering devices in all situations in which the latter are recommended. This applies especially if the user is doing hard or sustained work, and if the pollutants have poor warning properties or are particularly toxic. The SR 200 Airline is made of materials that are not liable to give rise to sparking when subjected to friction, which enables the device to be used in an explosive or fire-hazardous environment. Control valve, flow meter and warning whistle for temporary and continuous monitoring of the air flow are included.