Two-component, quick-cure Froth-Pak polyurethane foams quickly expand to fill cavities, penetrations and cracks greater than 2 in. (50 mm). They deliver a high yield and are packaged in easy-to-handle, self-contained, portable containers, designed for hard-to-reach air-sealing jobs. The Class A rating (flame spread of 25 or less) of Froth-Pak Foam Insulation kit qualifies it as an effective insulation for wall, attic and crawl space applications. Froth-Pak Foam Sealant has a flame spread of 25 at a maximum width of 4 in. and maximum thickness of 2 in.