Isopore Membrane Filter. 0.2 µm pore size, hydrophilic polycarbonate membrane, 25 mm diameter. 0.2 µm pore size, hydrophilic polycarbonate membrane, 47 mm diameter. 0.2 µm pore size, hydrophilic polycarbonate membrane, 13 mm diameter. 0.2 µm pore size, hydrophilic polycarbonate membrane, 25 mm diameter.