Nylon Membrane Filters, 0.22 Micron, 293mm, 25/Pk. Nylon membrane disc filters: 0.2 µm pore-size, 293 mm diameter, pack of 25. Hydrophilic, low-extractable, inert, durable material supported by an internal polyester web. Typically used for HPLC, microbiology, medical/clinical, and general filtration.