... insulation,Good fire-proof function 3 environmental High quality PU sandwich panel: Steel Thickness0.23~0.6mmPanel thickness50mm,75mm,100mm,125mm,175mm ... tile Structurethree layers:(1)upper layer is steel sheet,(2)the inner layer is PU sandwich,(3)the bottom layer is also steel sheetRockwool ... shipping Container or according to your demands High quality PU sandwich panel