Double Bubble Reflective Insulation (Foil/Foil) 4'x75' - 300 sq ftEcoFoil Double Bubble Foil Insulation is designed to improve comfort and moisture control in pole barns, metal buildings, basement walls, crawl spaces, and storage areasespecially in moderate and colder regions. The dual layer bubble core creates a built in thermal break that reduces heat transfer and helps prevent condensation and frost in areas with large temperature swings. At roughly 1 4" thick, this lightweight insulation installs quickly with