A flow indicator of a breathing apparatus that indicates a flow of a breathing-gas includes a structure within a conduitfor delivering the breathable gas, where the structure undergoes a change as aresult of a presence of the breathable gas or a movementof the breathable gas past the structure. The flow indicator also includes agas flow display that is actuated by the change in thestructure to visually indicate a presence or flow of the breathable gas, wherethe display is powered by the change in the structurewithout any outside power supply.
