Double Bubble Reflective Insulation (White/Foil) 4'x75' - 300 sq ftEcoFoil Double Bubble Foil Insulation is engineered for spaces that experience wide temperature swings, including pole barns, metal buildings, basement walls, crawl spaces, and storage units. The two layer bubble core creates an effective air gap that slows heat transfer and helps prevent frost and condensation caused by warm and cold surfaces meeting. At roughly 1 4" thick, this lightweight insulation installs quickly with simple tools. The white