Filter, Membrane, Pore Size 0.45 µm, Diameter 47 mm, 100/pk, plain, non-sterile | Hach USA - Overview
Whatman 10407714 Cellulose Nitrate MicroPlus-21 ST Filter Membrane, Sterile, 50mm White Circle with 3.1mm Black Grid, 0.45 Micron (Pack of 100): Science Lab Filter Membranes: Amazon.com: Industrial & Scientific