The Series of photoelectric smoke alarms with visual signaling appliance are designed for residential and commercial residential applications, including homes, apartments, hospitals, nursing homes, hotels and motels, in compliance with ANSI/UL 217, ANSI/UL 1971, applicable IBC/IFC/IRC Standards and NFPA 72. 120VAC with a 9V battery back-up, single/multiple station photoelectric smoke alarm with visual signaling appliance. The portable 7139LS are equipped with a 9 foot line cord that lets you instantly equip any room with a 177 candela visual and 90 decibel audible signal, all in one device. Upon activation, the alarm will emit a 90 decibel local audible signal and activate the high intensity strobe, flashing at a brightness at 177 candela 60 times per minute.