IDP-FIRE-CO-W combination fire and carbon monoxide (CO) detectors are plug-in, addressable devices that can detect and send separate signals for fire and CO. For fire, the detectors combine four separate sensing elements in one unit (smoke, CO, light/flame, and heat) to sense multiple components of a fire. This approach enables enhanced sensitivity to real fire with heightened immunity to nuisance particulate. For CO, the detectors' electrochemical sensing cells create separate signals for life safety CO detection. Released through the incomplete burning of various fuels, CO is a colorless, odorless and deadly gas that is virtually impossible to detect with the human senses. Because the potential exists for dangerous levels of CO to accumulate in almost any building, legislation mandating the use of CO detection in commercial spaces continues to increase across the US and Canada. The SIDP-FIRE-CO-W is listed to the UL 2075 standard for system-connected life safety carbon monoxide monitoring.