This is a remixed version of the original model by @mweisshaupt. This model strengthens the corners and adds some rigidity to the bottom to allow it to support the weight of the MX Master 3 and similar heavier mice. It's wide and tall enough to be able to fit larger mice as well.

No supports necessary. Just cleanup on the underside the screw holes if necessary.

Mounting instructions:

1. Mark four screwholes on underside of desk
2. Drill a 1/8 or less pilot hole into desk
3. Use 4 wood screws with washers attached to attach mount to desk
4. Slide your mouse in!