Camco's RV Vent Insulator with Reflective Surface blocks the sun's damaging rays. It fits standard 14-inch RV vents, reduces heat transfer and increases A/C efficiency. The vent insulator helps keep your RV cooler in the summer and warmer in the winter. Made of three layers - a reflective layer, a foam insulating layer and a synthetic fleece layer that provides UV ray protection. Features a full 2-3/4-inches of foam to help stop heat transfer.