The Kidde KN-COB-LP2 battery operated carbon monoxide alarm utilizes sophisticated electronic components to protect you and your family from the dangers of carbon monoxide. This alarm includes a slide-out battery door that gives immediate access to the batteries and a safety feature that makes it difficult to close the door without the batteries being installed. Inside cover of battery door features quick reference guide for what to do in case of an alarm. This easy-to-install alarm is suitable for all living areas and has a 7-year life and a 5-year limited warranty. The Kidde KN-COB-LP2 provides you and your family with a loud warning signal against the dangers of elevated carbon monoxide levels in your home. The battery operated CO alarm provides continuous monitoring of CO levels, even during power outages when AC-only units are not providing protection. This unit is battery operated and has 3 AA batteries included. The test/reset button tests the unit for proper operation and also resets the carbon monoxide alarm. A low battery signal alerts users when the batteries needs to be replaced. A green LED flashes every 30 seconds to indicate the unit is operating properly. The green LED will also flash before a CO reading is taken and when any button is pressed. A red LED will pulse and a loud alarm pattern will sound when a dangerous level of carbon monoxide is detected. The carbon monoxide alarm pattern is 4 short beeps, followed by 5 seconds of silence, followed by 4 short beeps with a corresponding red LED flash. This cycle will continue for 4 minutes and then change to 1 cycle every minute until the device is reset or the CO is eliminated. The alarm alerts user to replace CO alarm after 7 years of operation.