Aluminum foil reflective insulation air bubble sandwiched between layers of aluminum foil aluminum foil /bubble /aluminum foil foil can reflect up to 97 percent of the radiant energy that strikes it bubble provide a greater reduction of heat transfer. keep summer heat out and winter heat in so to help keep houses cool in the summer and warm in the winter used residential construction, industrial/commercial buildings, attics, warehouses, ect. Installed in walls, ceilings, and floor Roll size: 1.2m x 40m/roll, 48" x 125'/roll or custom-made