Smoke Alarm Battery Chemistry Alkaline Battery Location Back Battery Locking Pin Yes Battery Size 9V Communication Protocol Wireless Compatible With Not Applicable Detector Type Smoke Detector Features Hush Button Includes 9V Battery Number of Tandem Detectors 24 Power Source Removable Battery Sensor Type Ionization Photoelectric Visual Alert Type Red LED Volume Level 85 dB @ 10 ft Alarm Setting 30 ppm Battery Backup No Humidity Operating Range 85 Percent RH Hush Mode Yes