Carbon Monoxide and Gas Alarm Battery Chemistry Alkaline Battery Location Front Battery Locking Pin No Battery Size 9V Communication Protocol Not Applicable Compatible With Not Applicable Detector Type Explosive Gas/CO Detector Features Front Loading Battery Includes 9V Battery Number of Tandem Detectors Not Applicable Power Source Hardwired Sensor Type Electrochemical Visual Alert Type Digital Display Volume Level 85 dB @ 10 ft Battery Backup Yes Hush Mode Yes