Smoke & Carbon Monoxide Detector Combo, 10-Year Battery, Replacement Alert, 4 Count (Pack of 1)

2-in-1 Detection - This smoke and carbon monoxide detector combo alerts you to both smoke and fire events as well as poisonous carbon monoxide gas in one device. A photoelectric sensor identifies visible fire particles linked to slow, smoldering fires, while an electrochemical sensor detects carbon monoxide. An 85-decibel alarm sounds and a red LED shows the smoke detector is sensing smoke or fire. Powered by a lithium battery: removes the need for battery changes and offers dependable detection, even during power failures. The Test-Hush button allows for easy testing of the smoke detector and silencing of false alarms caused by cooking or shower steam. The alarm will automatically activate when attached to the mounting bracket; there are no pull tabs, no switches, everything is automatic. At the end of its operational period, the unit will chirp, indicating the alarm requires replacement. If that date is unknown, it should be assumed that replacement is needed