1)Optional for different leather and fabric 2)High-density foam insulation board 3)Paste density foam 4)very light weight We have been ... absorption spectrum , acoustic absorptivity>0.9 .2. Better effect for low ,middle.and high noise .3. fireproofing,no sands pollution ,strong ... sponge used to do high-end furniture, sponge, good elasticity, density is 1.5 times the normal sponge, prices are much ...