12V Atwood 31011 Carbon Monoxide & LP Gas Propane Detector Alarm RV Trailer

THIS UNIT REQUIRES 12 VOLT ELETRICITY TO OPERATE. DOES NOT USE A BUILT IN BATTERY. 3 WIRE CONNECTION. WALL CUTOUT SIZE: 3-9/16" WIDTH X 3-7/16" LENGTH X 1" FOR RECESS MOUNT INSTALLATION.