Professional use only. Openings that let air into a home rob homeowners of money, energy efficiency and comfort. Froth-Pak Foam Sealant is designed to fill gaps and penetrations greater than 4 In. quickly and affordably, helping eliminate unwanted airflow throughout a home. This low-pressure polyurethane foam expands quickly to fill cavities, wall and floor penetrations, cracks, and expansion joints. Review all instructions and (Material) Safety Data Sheet before use. Always wear appropriate PPE.