This listing is for a complete 3/16" tubing fitting assembly (full parts list linked here for an aqueous column or here for an organic column), item number 124391 or 124489.  Original selling price is $77 or $73 respectively through the company's website.  I'm sorry that I don't know whether these are for aqueous organic columns.  The o-rings are black (rubber?) and the bodies of the connectors feel like teflon/PTFE.  Perhaps that helps you if you're looking for these.

The bore hole through the end opposite the tube connection is approximately 1mm ID (shown in the third picture).