Chemglass, CG-472-02, Stopcock, Single Oblique, Hollow Glass Plug, High Vacuum, 4mm Bore, 17.35/50 Plug Size, 10mm OD Sidearms
Hollow plug, oblique bore stopcock is precision ground with corresponding numbers on barrel and plug. Lower vacuum chamber is evacuated via a separate hole in the plug which is not in the line of flow.