... different leather and fabric 2)High-density foam insulation board 3)Paste density foam 4)very light weight We have been ... .2. Better effect for low ,middle.and high noise .3. fireproofing,no sands pollution ,strong decorative ,easy to construct , ... middle is a sponge, a thickness of 1 cm, 3 cm, 5 cm, 8 cm sponges to choose from, ... bag above the cost of only U.S. $ 0.3-0.5 gap (we don't care the money, ...