Smoke Alarm Battery Chemistry Alkaline Battery Location Back Battery Locking Pin No Battery Size 9V Communication Protocol Not Applicable Compatible With Not Applicable Detector Type Smoke Detector Features Twist Off Mounting Bracket Flashing Red LED Power On Indicator Low Battery Indicator Includes Battery Number of Tandem Detectors Not Applicable Power Source Removable Battery Sensor Type Ionization Visual Alert Type LED Volume Level 85 dB @ 10 ft Battery Backup No