Description General description With 4 mm double oblique, high vacuum hollow glass stopcocks precision ground with corresponding numbers on barrel and plug. Lower vacuum chambers on stopcock are evacuated with a separate hole in the plug in order to hold the plug in the stopcock barrels. Beams are 22 mm O.D. with front-right and rear-left-right 10 mm hose connections. Distance between stopcocks is 75 mm center to center. Legal Information Synthware is a trademark of Kemtech America Inc.