Whatman 10401606 Mixed Cellulose Ester Circle ME Range (ME 25), plain, 0.45 um pore size, 25 mm, 100 per pack. Regular Price $101.29 Price $87.96. Add to Cart. Add to Wish List. Whatman 6875-2504 GD/X 25 mm Syringe Filter, PTFE filtration medium, 0.45 um (1500 pcs) Regular Price $2,733.72 Price $2,374.02.