Smoke Alarm Battery Chemistry Carbon Zinc Battery Location Back Battery Locking Pin Yes Battery Size 9V Communication Protocol Not Applicable Compatible With Not Applicable Detector Type Smoke Detector Includes 9V Battery Number of Tandem Detectors Not Applicable Power Source Removable Battery Sensor Type Photoelectric Visual Alert Type Red LED Volume Level 85 dB @ 10 ft Battery Backup No Humidity Operating Range 5 Percent to 95 Percent RH Hush Mode Yes Includes Batteries Yes