Medical Millex-GV Syringe Filter Unit, 0.22 µm, PVDF, 33 mm, gamma sterilized, A 33 mm diameter sterile syringe filter with a 0.22 µm pore size hydrophilic PVDF membrane. Comes in a pack of 50. SLGSV255F Millex-GS Syringe Filter Unit, 0.22 µm, A 25 mm diameter sterile syringe filter with a 0.22 µm pore size Mixed Cellulose Esters membrane.