Upgrades single 12 Volt Propane Gas alarms to a dual alarm that detects both Propane Gas and Carbon Monoxide (CO). Ideal for Class A Motorhomes, Class B Van Campers, Class C Mini-Motorhomes, Travel Trailers, Fifth Wheels, Truck & Folding Campers. Alarm Mute button silences alarm while RV is ventilated. Rapid recovery sensor resets when silenced or reactivates alarm if dangerous levels of Propane or CO remain. 12 Volt power means no missing or dead batteries to replace.