Smoke And Carbon Monoxide Combo Alarm

This detector is a 2 in 1 detector.Both can detect smoke and detect carbon monoxide.It's a good choice to have it in the place where use coal for heating.
A bi-color LED on each detector provides a local 360° visible alarm indication. They flash once every minute to indicate that power is on and the detector is working properly. The red LED flashes when the alarm occurs. When there is a fault condition indicating that the detector sensitivity is outside the listed limits or the battery is low, the yellow LED will flash.