Chemglass, CG-474-02, Stopcock, Double Oblique, Hollow Glass Plug, High Vacuum, 4mm Bore, 16.2/56 Plug Size, 10mm OD Sidearms
Hollow plug, double oblique bore stopcock is precision ground with corresponding numbers on barrel and plug. Lower vacuum chamber is evacuated with a separate hole in the plug which is not in the line of flow.