About this item Polycarbonate upper chamber with built-in stopcock. Stopcock accepts 1/4-Inch (6.4mm) I.D. flexible vacuum tubing. (Tubing sold separately). Polypropylene stopcock with a Teflon PTFE plug controls airflow to gently release vacuum Top vacuum chamber jar is molded of clear polycarbonate for full visibility and will withstand a full vacuum at room temperature. Includes 9-1/8-Inch diameter sealing plate. Chamber I.D. x Height: 7-7/8 x 4-3/8-Inch (20 x 11cm). Plate O.D. x Height: 9-1/8 x 1-3/4-Inch (23.2 x 4.4cm)