Advantages compared to traditional insulated sheet metal ductwork: Lower heat conductivity, higher thermal efficiency Low density, light weight Foamed with cfc/hcfc free materials, environment protective Hermetic seal ensures little air leakage It, ¡¥s corrosion protective, hygeian, and has a beautiful appearance. Foamed with closed-cell structure, it, ¡¥s water-proof and sound-insulated. Easy making, rapid installing and convenient maintenance saves cost. No protrudent flange on the connections, it can save a lot of building space. 3950*1200*20mm per sheet 10 sheets in one carton