Carbon Monoxide Alarm, Battery Chemistry Alkaline, Battery Location Side, Battery Locking Pin Yes, Battery Size 9V, Communication Protocol Not Applicable, Compatible With BRK Hardwired Alarms, Detector Type CO Detector, Includes 9V Battery, Number of Tandem Detectors 18, Power Source Hardwired, Sensor Type Electrochemical, Visual Alert Type LED, Volume Level 85 dB @ 10 ft, Alert Type Sound, Battery Backup Yes, Color White, Hush Mode Yes, Includes Batteries Yes