This case is designed for the DJI Mini 3 Pro. It has independently removable top and rear lids, which are held in place by circular magnets.
The case should fit in a decent-sized bag's side pouch and allow for easy access to the drone.
Magnets required:
Use N52 neodymium magnets for maximum strength. I used epoxy resin to attach the magnets, but any other strong glue should suffice.
Also see my hollow battery case design that should help contain some drone accessories.
The author hasn't provided the model origin yet.