Solved. Thank you @[email protected] . It’s an MHF4 connector. Will leave the post up for future people with the same question.

I’ve been playing around with an Orange Pi Zero 2W the last week. When I finally got the point of putting a case together, I was going to replace the little whip with a U.FL->SMA cable for an external antenna. However, the U.FL connector is too large for this.

This connector is the same form factor as U.FL but about half the size.

Is micro U.FL a thing? My Google-fu is failing me, the acronym stew is thick here, and I’d really like to wrap up this project with a nice external antenna. OrangePi hasn’t been helpful - they just call it “Wifi + BT Antenna connector” like that explains it all lol