1) Excellent filte function 2) Reusable,washable 3) Acid-resistant,alkalifast 4) Flexible,good tensile 20ppi Mesh Foam/Filter Sponge detail:1)Material ... ok6)Advantage:Excellent filte function, reusable,washable, acid-resistant,alkalifast, Flexible,good tensile7)Use: filter dust, air, liquid, equipment filter etc 20ppi Filter Foam