Whatman ® GD/X syringe filters cellulose acetate membrane, pore size 0.2 μm, diam. 13 mm, non-sterile, pk of 150 ea. pricing. WHA68711302. Whatman ® GD/X syringe filters Nylon membrane, pore size 0.23 μm, diam. 13 mm, non-sterile, pkg of 1500 ea. pricing. WHA68861312. Whatman ® GD/X syringe filters glass microfiber membrane, pore size 1.2