Millex-FG, 0.20 µm, hydrophobic PTFE, 50 mm. Background Information. Millex® syringe filter units with hydrophobic Fluoropore™ or Millipore Express® PLUS PES membrane are ideal for in-line sterilization of gases and venting sterile containers, and filters with Fluoropore™ membrane can also be used for sterilizing or clarifying organic