This valve does not require a sidearm because the plug has a bore that runs through it, sealing tight when closed and permitting gas/fluid to flow when open. The plug has machined-on serrated hose barbs (8 mm O.D.) for connection to standard heavy-wall vacuum tubing. This makes this plug an excellent choice for venting systems, Schlenk flasks, and gas purification tower drain plugs.
This item is available as a complete unit with the threaded glass barrel, solid plug, and fine thread control knob or purchase the parts individually.