... and heat insulation2.Smooth Surface3.no toxic.durable in water ,could filter air,dustExtruded polythylene foam could stand some press ... cell .,10-60ppi ,good elasticiry ,no toxic.durable in water ,could filter air,dust.1 .pu foam material2, reticulated, mesh, ... CM ≤ 10 4 .washable ,durable in water . 5 widely used in aquarium filter ,water filter ,air filter ,water pump,medical machine,cleaning kitch ...