Fire class DIN 4102 B1. Fire resistance, B2 up to 2 hours and B1 up to 4 hours depending on joint configuration. Acoustic rating 58 dB. Insulation factor 36mW/mK. Suitable for interior and exterior use. This is a rapid curing B2 Fire Class expanding foam with Genius Gun applicator for accurate trigger control and one-handed application. It offers excellent thermal and acoustic insulation properties. Ideal for filling around door and window frames, and pipe penetrations when DIN 4102 B2 fire class is required. Provides excellent yield and adhesion on most substrates. Reusable for up to 6 weeks. Attach bung after use.