Nalgene™ analytical filter funnel with cellulose nitrate membrane. Polypropylene upper; polystyrene. Ideal for use with filtering flasks or manifolds. Upper chambers are graduated at 150mL. Particularly useful for large volume analytical applications (as long as the membrane continues to flow). Convenient snap-away design with removable membrane. Safer and easier to use than cumbersome glass and metal funnels. Each package of 12 filters contains a Nalgene™ vacuum gasket to replace a stopper or adapter with 9/16" or larger opening. Membrane diameter is 47mm. Sterile. Certified.