... 2) Reusable,washable 3) Acid-resistant,alkalifast 4) Flexible 35ppi Liquid Filter Foam detail:1)Material: PU (polyurethane)2)Aperture: from 10ppi ... function, reusable,washable, acid-resistant,alkalifast, Flexible,good tensile7)Use: filter dust, air, liquid, equipment filter etc.Products 35ppi ...