Both Ionized and Photo Electric smoke sensorsDetects smoke from both smoldering and flaming firesLoud alarm to rapid responseSensors that detect non fires to reduce false alarms10 Year limited warranty– Anthony Dawson View on Amazon See also onAmazon. co. caBest Overall Smoke Detector First Alert SA320CN Dual Sensor 4. 9/5 Product RatingThe Kidde KN COSM B Battery Operated Combination Monoxide detector is a combination smoke and carbon monoxide detector. Carbon monoxide is an odorless and tasteless gas that can kill residents even when low amounts are inhaled. Instead of having both a carbon monoxide detector and a smoke detector, this unit combines the two into one unit.