While we do not currently have any case options for the Maxwell or MM-100, users have found this case to work well:
Geekria Shield Case (on Amazon)
Please note we do not officially endorse this product, so your mileage may vary. Other options may exist online.
In case you'd like to find a different option, the dimensions of the earcups are about 100mm, and the headphones are about 200mm tall.
While we do not have an ETA, we do plan on providing a case option in the future.