The 10x300mm PYREX® column is designed for general chromatographic column separations. The top is tooled for a No. 00 rubber stopper fit. A PTFE (Polytetrafluorethylene) Product Standard stopcock with a No. 2 plug is provided for better column control. Sealed into the column in a coarse porosity (40 to 60µm) fritted disc. The volume below the disc is minimized to prevent mixing and to allow clear, sharp, band definition. For more information on fritted products, please check the Guide to Selecting and Using Fritted Glassware in the Technical Information Listing. For replacement stopcock plugs, see No. 7681.