Dow Froth Pak 650 is a Class A fire rated spray foam insulation kits are complete portable two part polyurethane spray foam systems. FROTH-PAK polyurethane foam is a two-component, quick cure, closed cell foam that fills cavities, cracks and expansion joints for insulation and air sealing. Air infiltration accounts for 25%-40% of a home's energy loss, FROTH-PAK stops that energy loss. FROTH-PAK Foam Insulation kits can be used to insulate stud wall cavities up to 2" thick, cold floors above unheated areas, crawl spaces, attic walls, and ceilings when covered with a code-approved barrier. The kit can be restarted and reused for up to 30 days after first startup. The Froth Pak 650 kit yields up to 650 board feet of foam. The Froth Pak 650 kit yields up to 650 board feet of foam (One board foot = 12"x12"x1"), 1.75 foam density.