Great Stuff Big Gap Filler Insulating Foam Sealant, 20 oz. is a high-quality expanding urethane foam designed to fill large areas quickly and permanently. It is i for filling holes, cracks, or gaps that require a complete airtight and waterproof seal but are too large to be filled with ordinary caulk. This foam expands to approximately three times its volume, becomes tack- in about 45 minutes, and is fully cured within 12 hours. Each can includes a dispensing apparatus for easy application. The product is UL classified and contains no CFCs, making it an effective and environmentally conscious solution for insulation and sealing needs.