1>foam filter,polyurethane foam materials,reticulated and open cell(10ppi--70ppi) 1: foam filter has different mesh size (8ppi-60ppi),2: foam filter, polyurethane foam materials .reticulated, open cell3: high resilient ,good colors and good air permeability .Widely used for aquarium filter, water pump, air filter and other filtering business .4:It's durable in water and low cost .5: Pond filter, ...