... dust aborsorbing 2.corrosion resistance 3.high efficient filter 4.use: clean/ filter filter sponge Factory directly sell,low price,good quality, ... size,packing ,colour can according to your request.filter sponge 1) Material: PU sponge,10ppi,15ppi,20ppi,25ppi ... customers requested size.5) Shape:heart,square,round,customers design shape are welcomed.Advantages:Factory directly sell,with high ...