For aqueous samples, it is preferable to use a hydrophilic membrane (GHP, PVDF or Nylon) versus a hydrophobic. Configuration: Filter Element & Housing Assembly; Filter Medium Material: Nylon, Polytetrafluoroethelene (PTFE), Polyvinylidene Fluoride (PVDF), Polyethersulfone (PES), Glass Fiber, Other; Filter Type: Syringe Filter; Hold Up Volume