The Kidde 260-CO is a commercial grade carbon monoxide (CO) detector that can be connected to a UL listed control panel. It is an accurate and reliable means of alerting building occupants of potentially dangerous levels of CO in a protected area. The internal electro-chemical sensor communicates with a sophisticated on-board microprocessor that accurately tracks CO levels over time. The 260-CO has a longer than normal, 10 year service life, compared to 6 years for most others. When the detector approaches end of life, a warning is indicated at the detector as well as the control panel the detector is connected to. An integral temporal 4 sounder activates when the detector alarms. The detector can also be tandem connected to other 260-COs so that when one goes into alarm, the sounders in the others also activate.