For microbiological testing. Use in vacuum manifolds and filter flasks. Each sterile filter funnel consists of a polypropylene upper, a high-impact polystyrene collar and a cellulose nitrate membrane. Graduated upper separates easily from the lower for easy access to the membrane. Funnel adapters allow use with No. 8 stoppers; six adapters are included with each case. The 0.45 µm pore size membranes are certified for water quality work including coliform analysis. 47 mm membrane diameter. For laboratory use only. Not for in vitro diagnosis or parenterals.