I think this question might not be as stupid as it sounds. I have a pair of Alclair Duals and wanted to get a short cable for them for use with my new FiiO BTR3. The only listing I could find on Aliexpress was this one, which offered a short cable in 0.75, 0.78, MMCX and other variants. The TF10 connectors pictured are what I wanted (with the pins coming out of an extrusion on the end of the connector) and would fit my Alclairs fine. After searching around here, I saw some people say to go for 0.75mm if you were unsure as you'd just stretch the sockets with 0.78mm. So I did. And they sent me cables with pins coming out of a recess in the connector, which won't fit my monitors. After arguing back and forth with the Aliexpress vendor who was insisting I must want 0.78mm pins and me saying the pin size wasn't the problem, we got to this point: To which he says, "All the 0.75mm connectors look like that, you must want 0.78!". But here's the original cable on the bottom, and what they sent me on the top: They look pretty damn close to me. Google image searching "0.75 tf10" vs "0.78 tf10" is inconclusive (many recessed connectors show up in the 0.78mm search; the 0.75mm search almost but not exclusively shows recessed connectors.) So does 0.75 vs 0.78 imply anything about the connector design? Or are both pin sizes available in recessed and extruded styles? How does one distinguish?