XPS Insulation (Extruded Polystyrene): "XPS" commonly refers to extruded polystyrene insulation. This type of insulation is known for its closed-cell structure, providing good thermal resistance and moisture resistance. It is often used in various construction applications, such as insulating walls, roofs, and foundations. B1 Fire Rating: The "B1" component might refer to a fire rating. In some fire classification systems, materials are rated based on their fire resistance, and "B1" could indicate a certain level of fire resistance. For example, in the European fire classification system (Euroclass), B1 represents a material with limited combustibility.