Pall 66068 Metricel GN-6 Membrane Filter, Grid Pattern, 0.45 um Pore Size, 47 mm Diameter (Pack of 1000) Certified for potable, waste, process and natural water testing For microbiological analysis using the Membrane Filter (MF) Technique Hydrophilic mixed cellulose esters filter media 65 mL/min/cm2at 0.7 bar (70 kPa, 10 psi) typical water flow rate