A 750ml FR (Flame Retardant) gun foam is a professional-grade, fire-rated polyurethane expanding foam formulated for sealing joints, gaps, and penetrations where fire-resistance compliance is required. Applied using a standard mechanical foam applicator gun, it expands to fill irregular voids, delivering high thermal insulation, acoustic damping, and smoke-tight sealing properties. Certified to international fire safety standards (such as EN 1366-4 / B1 ratings), it resists flame spread and maintains structural integrity during exposure to extreme temperatures, making it essential for fire-stop installations around door frames, pipe penetrations, and structural wall joints.