Whatman Filtration Devices, 0.2um, .45um, Pore Size: 0.2um 0.45um. Whatman 6902-2504 GD/X 25 mm Sterile Syringe Filter, glass microfiber filtration medium, 0.45 um (50 pcs) Regular Price: $203.99. Price $177.39. Add To Cart. Whatman 6901-2504 GD/X 25 mm Sterile Syringe Filter, cellulose acetate filtration medium, 0.45 um (50 pcs) Regular Price