Improved Logitech MX Master 3 Case. 

Improvements to the original model:

• larger magnet holes (cylinder 5x5mm)
• hole for indexing pin (2.7mm)
• more asethetically pleasing “bump” around the magnet

Now you can use stronger magnets and indexing pin.  The case closes shut nicely and is fully constrained.

There is also enough space to add a lining to further protect the mouse inside.

As a bonus the case has smoother outside with no intrusive bumps.

The last two photos are of the original design. Included mainly for comparison.