Check the listing for details. 12V Atwood 31011 Carbon Monoxide & LP Gas Propane Detector Alarm RV Trailer. Condition: New. Listed at 26.95 USD. 12v Atwood 31011 Carbon Monoxide & LP Gas Propane Detector Alarm RV Trailer Manufacturer 2021-2022 GOOD FOR 7 YEARS AFTER THE UNIT IS POWERED ON. 7 YEARS DOES NOT START TILL THIS UNIT HAS BEEN POWERED ON FOR THE FIRST TIME. WALL CUTOUT SIZE: 3-9/16" WIDTH X 3-7/16" LENGTH X 1" FOR RECESS MOUNT INSTALLATION. THIS UNIT REQUIRES 12 VOLT ELETRICITY TO OPERATE. DOES NOT USE A BUILT IN BATTERY. 3 WIRE CONNECTION. New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is applicable). Packaging should be the same as what is found in a retail store, unless the item was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag. See the seller's listing for full details12v Atwood 31011 Carbon Monoxide & LP Gas Propane Detector Alarm RV Trailer Manufacturer 2021-2022 GOOD FOR 7 YEARS AFTER THE UNIT IS POWERED ON. 7 YEARS DOES NOT START TILL THIS UNIT HAS BEEN POWERED ON FOR THE FIRST TIME. WALL CUTOUT SIZE: 3-9/16" WIDTH X 3-7/16" LENGTH X 1" FOR RECESS MOUNT INSTALLATION. THIS UNIT REQUIRES 12 VOLT ELETRICITY TO OPERATE. DOES NOT USE A BUILT IN BATTERY. 3 WIRE CONNECTION. New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is applicable). Packaging should be the same as what is found in a retail store, unless the item was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag. See the seller's listing for full details