MF-Millipore ® Membrane Filter, 0.45 µm pore size, 47 mm diameter, mixed cellulose esters (MCE) membrane, hydrophilic, white, 100 discs HVLP04700 Durapore ® Membrane Filter, 0.45 µm, 0.45 µm pore size, hydrophilic PVDF, 47 mm membrane GVWP04700 Durapore ® Membrane Filter, 0.22 µm, 0.22 µm pore size, hydrophilic PVDF, 47 mm membrane