Whatman 7182-002 Cellulose Nitrate Membrane Circle, plain, 0.2 um pore size, 25 mm, 100 per pack. Regular Price $153.32 Price $133.15. Add to Cart. Add to Wish List. Whatman 10401312 Cellulose Nitrate Membrane Circle, plain, 0.2 um pore size, 47 mm, 100 per pack. Regular Price $186.05 Price $161.57.