This 1000mL bottle top filter from the Rapid-Flow™ series consist of a polystyrene housing with a 90mm Supor® machV polyethersulfone (PES) membrane for a faster flow rate. Filter securely screws onto glass media bottles with 33mm neck sizes. Allows direct filtration of liquid into sterile glass media bottles. CAUTION: Use only sterile bottles designed for use with vacuum. Always use safety shield during vacuum procedures. This product is not intended for use in direct patient care or diagnostic procedures. Filter features molded-in graduations and a side-arm with quick-disconnect tubing adapter. Blue collar. Material: polystyrene housing with a Supor® machV PES membrane. Filter capacity: 1000mL. Fits bottle neck size: 33mm. Membrane diameter: 90mm. Pore size: 0.2µm. 12/Case. Nalgene® #: 597-3320.