The combination smoke and carbon monoxide alarm shall be Kidde model KN-COSM-IBACA or approved equal. It shall be powered by 120 V AC, 60 Hz source with two AA battery backup. The temperature operating range shall be between 4.4˚C (40˚F) to 37.8˚C (100˚F) and the humidity operating range shall be 10%–95% relative humidity, non-condensing.