Abstract: A hand-held pressurized fluid powered audible alarm includes a housing in which is mounted a pressurized container having a deflection responsive valve and outlet member projecting therefrom. A horn body is mounted on and in fluid communication with the member and a spring loaded plunger carried by the housing is provided to contact and displace the horn body thereby deflecting the member to supply pressurized fluid for sounding the alarm. The plunger is normally retained spaced from the alarm by a removeable pin passing transversely through the plunger shaft. A ring coupled to the pin is pulled to rapidly remove the pin and irreversibly activate the alarm.