Carbon Monoxide and Smoke Alarm Battery Chemistry Alkaline Battery Location Side Battery Locking Pin Yes Battery Size 9V Communication Protocol Not Applicable Compatible With Not Applicable Detector Type Smoke/CO Detector Includes 9V Battery Number of Tandem Detectors Not Applicable Power Source Removable Battery Sensor Type Electrochemical Ionization Visual Alert Type LED Volume Level 85 dB @ 10 ft Alert Type Sound Battery Backup No Color White Detects Smoke Hush Mode Yes