... membrane aperture has 0.22, 0.45, 0.8 and 1.2um. Membrane material has:CN-CA, Nylon, PVDF, PTFE. ... Series ¢13 mm ¢25mm0.22, 0.45, 0.8, 1.2(um)CN-CAHydrophobic Series ¢13 mm ¢25mm0.22, 0 ... .45, 0.8, 1.2(um)Nylon Hydrophobic Series ¢13 mm ¢25mm 0.22 ... the membrane aperture, supply utmost protection for your instrument and GC column.6. Stable quality filtration membrane, each patch of the ...