Rugged 24/29 ST taper stopcock with tooled hose connection serves as the vacuum inlet, designed so its manipulation is not affected by the vacuum. To introduce vacuum into the desiccator, loosen the stopcock to disengage the PTFE plug from contact with the glass. A half turn from this position closes the desiccator. This design eliminates the need for grease. Approximate bowl volume as stated in description. WARNING: Do NOT heat or subject to pressure! Rated 1-atmosphere vacuum.