Keep your family safe with this easy-to-use plug-in carbon monoxide alarm; it works with any standard outlet and also has a battery backup for continuous monitoring of Carbon Monoxide levels, even if there's a power failureFeatures an advanced electrochemical carbon monoxide sensor that accurately detects carbon monoxide levels, no matter where the detector is placed in the roomSimple to use, with a single test/silence button; a loud 85-decibel alarm sounds when Carbon Monoxide levels reach dangerous levelsTo ensure complete protection make sure to place one on each level of your home and in each bedroom7-year limited warranty; equipped with end-of-life signal chirp, so you know when it's time to replace the unit for safetyAll First Alert CO alarms are rigorously tested to meet UL standards. Item Length is 3.4 inch , Item Width is 1.38 inch and Item Height is 5 inch