Argos BPV4525 PVDF Membrane Sterile Bottle Top Aspirator Vacuum Filtration Unit, 0.45 micrometer Pore Size, 250mL Capacity (Case of 12) Membrane material: PVDF in .45m; capacity: 250 mL Graduations are engraved to provide more accuracy; hose connector fits multiple hose diameters Certified non-pyrogenic and gamma irradiated Funnel is manufactured from optically clear polystyrene; bottle and filter adapter are manufactured from 100% virgin polypropylene Individually wrapped with peel-open packaging; receiver bottle cap is individually wrapped