This Model lets you mount a BOBOVR B2 Battery securely to a Pico4 headset similar to what the BOBOVR M2 PRO head strap does. I used broken one of these as a donor so I included the possibility for adding a PCB with pogo pins in the base.
Assembly of those 2 parts requires some M3 inserts as well as short (6-8mm) M3 screws.
If you don't have a broken M2 Pro you can just use the mount part as is with some magnets. Since I could harvest the magnets from the broken m2 as well the magnet sizes might not match what you have at hand. In this case you can edit the .scad files to taste.
The author hasn't provided the model origin yet.