Great Stuff Big Gap Filler Insulating Foam Sealant is a ready to use expanding polyurethane insulating foam sealant that fills, seals and insulates gaps up to 3 inches. The average home has a half mile of gaps and cracks where air and moisture can enter. Seal out energy loss and improve comfort with Great Stuff Big Gap Filler Insulating Foam Sealant. Great Stuff expands to take the shape of gaps, creating a long lasting, airtight and water resistant seal. It's a simple way to minimize unwanted air flow and reduce condensation. New Smart Dispenser design eliminates mess and product waste by providing a precise application with no drips. The application is maneuverable and intuitive to use with a simple, trigger gun which saves time. The Smart Dispenser allows the user to reuse Great Stuff for up to 30 days.