Membrane Circles Cellulose Nitrate, White Gridded Sterile 0.45µm 47mm | Whatman 7141-104 Descriptions : Cytiva #39;s Whatman 7141-104 WME Sterile Gridded White Mixed Cellulose Ester Membrane Filter amp; Pad with 3.1mm Black Grid, Pore Size: 0.45µm, Diameter: 4.7cm (Pack of 100) - 0.45µm mixed cellulose ester membrane filter with grid - sterile - 47mm - Gridded surface (3.1mm intervals) make filters ideal for colony counting - Special non-toxic ink used is completely free from bacterial growth inhibitors - Performance improvements include very narrow pore size distribution and low levels of extractables - Has a noticeably improved flexibility; is made to tolerate abuse - Pack of 100 - Manufacturer: Cytiva - Manufacturer Part No: WHA-7141-104