Pall 0.22 um PTFE syringe filter for solvent prefiltration. These polytetrafluoroethylene PTFE syringe filters are available in two different porosities 0.45 µm and 0.22 µm and two diameters 25mm and 13mm. We offer them with a prefilter or without in glass fiber or polypropylene as well as the option of hydrophilic or hydrophobic filters.