China Factory Good Soundproof Waterproof Expanding Polyurethane Foam 750ml PU Foam Sealant Spray Filling Fireproof and Waterproof: Provides excellent sealing work with fire and water resistance. Low Foam Pressure: Prevents warping or deformation of windows and doors. Closed Cell Structure: Does not absorb moisture, ensuring long-term durability. Quick Setting Formulation: Can be cut or trimmed in less than 1 hour after application. Flexible Performance: Will not crack or dry