First Alert CO5120BN AC Powered Carbon Monoxide Alarm

First Alert Hardwired Carbon Monoxide Alarm - First Alert hardwired carbon monoxide detector with battery back-up. Features an electrochemical sensor which detects carbon monoxide gas and measures the concentration. Sounds a loud 85 decibel alarm when potentially harmful level is reached. 2 silent features; unwanted alarms and low battery silence. Instant test/reset button. 9-volt battery included. Battery life varies according to use and application. Recommended for professional installation only. UL (Underwriter's Laboratories) listed. White. - Type: Hardwired, Voltage: 120V, Battery Life: Varies According To Battery Life, Sensor Type: Electrochemical, Dimensions: 5-3/5 In. W x 1-9/10 In. H x 5-3/5 In. L, Battery Back-Up: Yes, Alarm Type: Carbon Monoxide, Decibel Level: 85dB, Battery Type: 9V Battery, Batteries Included: Yes, Color: White, UL Listed: Yes, Warranty: 7-Year Limited, Pkg Qty: 1, Package Type: Box