These are high vacuum stopcocks with arms at 90 degrees with variable openings from 0-3 mm to 0-15 mm

An ultimate vacuum of 10-7 can be realized with the standard three O-rings. Smooth acting semi-needle valve permits fine adjustment of opening. Plugs available in bakeable PTFE or glass with Nylon handle. Reference marks on body aid in repetitive setting. Supplied with FETFE O-rings. Plug only and replacement O-rings available