An airtight, premium-grade polyurethane expanding foam filler designed specifically for sealing around windows and doors. This product offers exceptional thermal and acoustic insulation properties, ensuring superior performance. Once fully cured, it creates a completely airtight seal. Utilising FLEXIFOAM® technology, it exhibits remarkable flexibility post-curing, enhancing its durability. With its single-component Gun Grade formulation, it facilitates rapid curing and provides primerless adhesion to most construction materials.