Handi-Foam® is an expanding sealant which is a moisture-cure polyurethane foam. It is used to seal, bond, retrofit, insulate and deaden sound in electrical, plumbing, air-conditioning and refrigeration applications. It expands 2 to 3 times its extruded bead and is rated R-5 for each inch of foam. Specifically designed to be dispensed as a bead for filling cracks. Substrate must be clean, firm of loose particles and dust.