Nalgene 194-2520 Polyethersulfone Sterile Syringe Filter Membrane, 25mm, 0.2 Micron (Case of 50) Membrane diameter: 25mm, pore size: 0.2m; sample volume size: 10-50ml Material: acrylic housing with polyethersulfone (PES) membrane Offers higher flow rates, lower protein binding, and lower extractables than competitive cellulosic membranes Inherently hydrophilic; contains no external wetting agents Certified sterile, non-cytotoxic, and non-pyrogenic; supplied individually blister-packed; not autoclavable