The 640 addressable audio/visual alarm devices are suitable for connection to 2-wire addressable fire detection And alarm systems. 640 is loop-powered and activation is initiated by a dedicated initiation message from the control and indicating Equipment. Up to 125 devices can be connected to each alarm zone loop. Visual, audible and audio/visual models available Red or white body available for audible alarm device Loop-powered from control and indicating equipment Operates when a dedicated activation message is received from the control and indicating equipment Loud sounder output of 85 db at 1 m Long-life leds Low quiescent current Dip switch address setting