OK so they went in this order...
Version 1 - Blue metal case
Version 2 - Black plastic case. My original version as seen in my video.
Version 3 - Blue plastic case. Introduction of the built-in DSP.
Version 4 - Grey plastic case. Introduction of the OEM microphone connection.
There have been 18 MCU firmware updates since first introduction, the last one being July 2025, so a new box bought now should be up to date. They've slowed down with the updates as they are now very stable, obviously there were more earlier on as issuse were found. They've worked closely with the Mr12volt community and listen to issues and suggestions (the DSP being a big one).
Hope that helps.