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 Features Test Button Includes Mounting Hardware Number of Tandem Detectors Not Applicable Power Source Removable Battery Sensor Type Photoelectric Visual Alert Type LED Volume Level 85 dB @ 10 ft Battery Backup No Form Factor Slim Profile Hush Mode Yes Includes Batteries Yes