Carbon Monoxide Alarm, Battery Chemistry Alkaline, Battery Location Front, Battery Locking Pin Yes, Battery Size 9V, Communication Protocol Not Applicable, Compatible With Not Applicable, Detector Type CO Detector, Features Front Loading Battery, Includes (2) 9V Batteries, Mounting Anchors, Screws, Number of Tandem Detectors Not Applicable, Power Source Removable Battery, Sensor Type Electrochemical, Visual Alert Type LED, Volume Level 85 dB @ 10 ft, Alert Type Sound, Battery Backup No