Kidde Worry-Free DC Smoke/CO Combo Alarm (Photoelectric)

Protecting against fire and CO, this alarm comes with a sealed lithium battery for 10 years of worry-free protection. And it uses both an advanced photoelectric sensor for smoke and an electrochemical sensor for CO. These two features communicate, too, automatically adjusting the sensitivity to better identify real hazards and reducing nuisance alarms when cooking. The alarm is also self-activating and comes standard with a test/hush button and LED indicator.
NOTE: Cannot ship to AK, HI, PR, or Catalina.