... Best insulation,Good fire-proof function 3 environmental High quality PU sandwich panel: Steel Thickness0.23~0.6mmPanel thickness50mm,75mm, ... ceilingLengthAccording to customer's request,less than 11.8mMaterialsInner is PU sandwichsides is GalvanizedColor steel tile Structurethree layers:(1)upper ... layer is steel sheet,(2)the inner layer is PU sandwich,(3)the bottom layer is also steel sheetRockwool ...