Nalgene 300 Series Reusable Polysulfone Filter Holders with Receiver eliminate the need for a manifold and/or breakable glass vacuum flask. Receiver is graduated. Two side-arms allow connection to vacuum line; also accept syringe filters. Chamber accommodates 47 or 50mm membranes (not included). Tubing adapter can be stuffed with cotton for sterile venting; accepts 1/4-in. to 5/16-in. (6- to 8-mm) I.D. vacuum tubing. Cover allows convenient storage of sterile filtrate. WARNING! All NALGENE Filterware is for research use only, not for in vitro diagnosis or parenterals.