95-904 | By adding this module to either the Calrad 95-898, 95-899 alarms, or any other standard control center, you can have a 24 hour panic override switching circuit, even though your alarm is on or off. When triggered, this control will activate either the alarm bell, siren or another independent alarm device. May also be used for non-supervised open circuit heat detection. Size: 3" (L) x 2 1/2" (W) x 1 1/4" (H).