Single Bubble Insulation - Foil/Foil - 4' x 125' (500 sq ft)EcoFoil Single Bubble Foil Insulation provides an effective radiant heat solution for moderate climate structures such as pole barns, metal buildings, basement walls, crawl spaces, and storage units. Its polyethylene bubble layer forms a built in air gap that slows heat transfer and helps limit frost and condensation caused by temperature differences on opposite sides of the material. At approximately 1 8" thick, this lightweight insulation is easy to