0.45um PTFE syringe filter for HPLC analysis. Hydrophobic PTFE Membrane – The PTFE needle filter material is a PTFE membrane, with the naturally hydrophobic, it with broad chemical compatibility and strong chemical stability and inertia, strong hydrophobicity. Uniform Pore Size – PTFE Syringe Filter with uniform pore size, high porosity, and high retention efficiency. 13mm disc diameter, 0.22μm, pore size, 100 pcs barreled packed.