Kidde P3010K-CO Smoke And Carbon Monoxide Detector, specially designed with a loud 85 Decibel alarm that sound off when it detects smoke or carbon monoxide, yet its intelligent multi sensor alarm that reduces nuisance alarms (like from a tea kettle), and it has Test / Hush Button to test the alarm to confirm the alarm sounds off, or you can push the button to silence the alarm. This alarm features a Photoelectric Sensor that detcts visible particles associated with smoldering fires sooner than ionization alarms. This Combination detector uses a 10 year life battery, so the alarm works during power outages, and it has an end of life chirp to notify you when the alarm has reached it's end of life. This Alarm complies with the following authorities: Underwriters Laboratories (UL), Federal Housing Administration (FHA), Housing And Urban Development (HUD), National Fire Protection Association (NFPA), California State Fire Marshal (CSFM). Kidde recommends a CO alarm be installed on each level of the home, ideally on any level with fuel burning appliances and outside of sleeping areas. See the user guide for further information.