The unique Torion connection ensures an airtight seal between tubing and reaction vessels when transferring air-sensitive materials.5/16 in. O.D fits a #8 Torion, 1/2 in. O.D. fits a #14 Torion, and 3/16 in. O.D fits a #5 Torion. Hard-wall transfer tubing (e.g. PP or PTFE) is inserted through the threaded polypropylene bushing and PTFE-coated sealing ring of the adapter Turn the bushing to make an airtight compression seal with the tubing Use the optional solid-glass plug to make an airtight Torion seal when the transfer tubing is not in use O.D. refers to the tubing outer diameter