750ml High Foaming Fireproof Polyurethane Foam Sealant for Building Cracks and Gaps

750ml High Foaming Fireproof Polyurethane Foam Sealant for Building Cracks and Gaps. Passed authoritative lab tests, meets Class B2 flame retardant standard, perfect for residential & general construction fire sealing demands. Oxygen index more than 26%, self-extinguishes within 3 seconds after leaving fire source to stop flame spread. Adopts high-efficiency flame retardants, prevent gun clogging and tank valve blockage, smooth on-site construction & less rework. Adequate initial expansion for tight gap filling, great sound & thermal insulation. Low post-expansion force, no deformation of window frames, wall panels after curing.