Oct 29, 2021 · EZBio® Vent Filter, 0.22um Phobic PTFE, Non-Sterile, 50mm Carboy Vent Filters are used for hydrophobic venting and solvent filtration applications. The PTFE filter membrane is ideal for maintaining purified water stored in carboys, or for sterile venting during a slow exhaust/liquid autoclave cycle of EZgrip carboys.