Ventilation screw caps GLS 80, DURAN® with ePTFE membrane, blue, 2 unit(s)Ventilation screw caps GLS 80, DURAN with ePTFE membrane, blue Material: PP, with welded in PTFE membrane. Autoclavable: yes. The membrane, made of expanded PTFE with a pore size of 0. 2 m enables a sterile gas exchange and prevents aqueous liquids with high surface tension from passing through it. Pressure equalisation during steam sterilisation autoclaving of media or buffer solutions in bottles up to a volume of 5 litres Sterile gas exchange for