The Soudal Genius Gun Fire & Acoustic Expanding Foam 600ml B1 is a high-quality, self-expanding polyurethane foam specially designed for fire and soundproofing applications. With its impressive expansion rate, this foam fills and insulates all types of small gaps and cavities effectively. Its also rated B1 for fire resistance, making it ideal for use in areas where safety is a priority. The Soudal Genius Gun technology makes application easy and precise.