Pur 7 Foam is a Fire-Retardant Class B2 low expansion handheld Expanding Foam that uniquely stops expanding when it meets resistance. Ideal for filling, sealing, insulation and prevention of thermal bridges and is soundproof. Pur 7 adheres to most building materials and can be sanded, painted, and plastered after 60 mins. Supplied in a 750ml aerosol.