The Kidde KNCOBLCBA is the ideal carbon monoxide alarm for buildings where theft or tampering is a concern. Quick and easy to install, this AC/DC carbon monoxide alarm plugs directly into a standard non-switch outlet. LED indicators light up green when power is on and red when the unit is in alarm mode. It features electromechanical sensing technology to monitor carbon monoxide levels, a 9V battery backup for continuous monitoring even during power outages, and an 85-decibel alarm. This alarm also features a low battery hush, silencing the low battery chirp warning for up to 12 hours to maintain monitoring. The tamper resistant feature deters theft and tampering by going into constant alarm mode if the unit has been unplugged or has come loose from the wall outlet. The sleek, low profile design makes this unit the perfect choice for any decor while providing certainty the air quality is safe.