Whatman 6870-1304 Nylon GD/X 13 Syringe Filter, 13mm, 0.45 Micron (Pack of 150): Science Lab Syringe Filters:. The GD/X syringe filter is the ideal choice for the preparation of hard-to-filter samples. Constructed of a pigment-free polypropylene housing with a prefiltration stack of GMF 0 (graded density) and GF/F glass microfiber media, this filter eliminates sample contamination and allows you to filter even the most difficult samples with less hand pressure. GD/X syringe filters can process three to seven times more sample volume than standard syringe filters. Membrane: Nylon. Retention: 0.4µm. Filtration Area: .3 sq cm. Diameter: 3mm. Inlet: Female Luer Lok. Outlet: Male Slip Luer. 0/Pack. #: 6870-304. . . .