Whatman 6869-2502 GD/X 25 mm Syringe Filter, nylon high charge (positive), nylon filtration medium, 0.2 um (150 pcs) Regular Price $611.15 Price $531.43. Add to Cart. Whatman 6887-2502 GD/X 25 mm Syringe Filter, regenerated cellulose filtration medium, 0.2 um (150 pcs) Regular Price $781.47 Price $679.54. Add to Cart.