WHATMAN 7184-002 Filter Membrane,0.45um,25mm,PK100 New. US Seller. Filter Membrane, Pore Size 0.45um, Diameter 25mm, Material Cellulose Nitrate, Temp. Range 80 Degrees C, For Use With Sample Preparation, Microbiological Studies, Filtration of Aqueous Solutions, Package Quantity 100. Fixed Price $ 25.00