BRand New inside original, opened box.

Kidde 900-CUAR Hardwired Smoke and Carbon Monoxide Alarm, Interconnectable With AA Battery Backup Combo Model# 21032250 The 900-CUAR Hardwired Smoke & Carbon Monoxide Detector, which can be interconnected and comes with AA battery backup, safeguards you and your loved ones from two potential dangers: fires and the harmful presence of carbon monoxide (CO). This combination smoke and carbon monoxide detector boasts self-testing components that continuously verify the alarm's functionality. It utilizes a photoelectric smoke sensor for improved detection of larger, visible fire particles. Key Features: CO Sensor Type: Electrochemical. Delivers precise and constant CO protection throughout the device's lifespan, maintains stability amidst temperature and humidity fluctuations, and resists reactions to household gases that could lead to false readings or decreased sensitivity. Smoke Sensor Type: Photoelectric. Has the ability to detect visible fire particles associated with slow, smoldering fires earlier than an ionization sensor. 2-AA batteries serve as backup power for the smoke detector-carbon monoxide detector combo during brief power outages. Includes a mounting bracket for quick and effortless installations in four different orientations.