This is a remix of I_d's neat Molle Clip for GPSmap handhelds.

I made one to use with my Garmin GPSmap 60Cx. Used it.Loved it.Broke it!
So beefed it up a bit....and back in GPS-trail-tracking business.

Prusa

i3 MK3

.3

15% honeycomb

3 perimeters. 3 solid top and bottom layers.

Imported the original STL into Tinkercad. Exported as an SVG.
Started a new Fusion 360 project and inserted the SVG.
Had to scale to correct dimension (I forgot to check/set units in tinkercad), then extruded and sketched up desired changes.

Recommend PETG, or Nylon if you have it.