... is the new green environmental protection material, this kind of air duct heat preservation, soundinsulated, artistic, durable, clean, health, nature, ... the energy conservation, environmental protection, it will be the traditional air duct perfect renewal product. Dimension: 3900×1200×20+ 1mm ... -Combustible Class "O" 7) Water Absorption 1.9%8)Max. Smoke Density 2%9)Working Temperature -150 °C to 150 ...