Kidde. A complement to the smoke detector from the same product line, the Silhouette Carbon Monoxide Alarm is a low-profile AC/DC-powered unit that operates on a 120-volt power source. The sealed rechargeable battery backup lasts for the seven-year life of the alarm for a maintenance-free design. Using electrochemical CO sensing, the alarm interconnects with other Kidde alarms to provide early warning of carbon monoxide or fire. A digital display offers easy viewing of current CO levels. 800.880.6788.