Photoelectric Smoke Detector, With Heat, Finish White, Single Gang, 3 In. Round, 4 In. Octagonal Mounting, Alarm Current 60mA Max, Standby Current (uA) 70, Height (In.) 2, Width (In.) 6, Ambient Temp. Limits (F) 32 to 100, Humidity Range ( Percent RH) 0 to 95 Non-Condensing, Voltage 6-33VDC, Standards UL, CSFM, Includes Base, For Use With 1EXW9, 1EXY1, 1EXY2 Fire Alarm Initiating DevicesPhotoelectricWhen activated, devices send signals on a hardwired connection to initiate an alarm.Units detect dark or thick smoke. Respond quickly to slow smoldering, high-smoke fires.Smoke DetectorsLEDs on units give visual indication of alarm activation. Include test11 switch.UL and C-UL Listed.Operating voltage: 8.5VDC to 33VDC