Summary

Stand to elevate your detector from the ground and make it more stable, snaps to the bottom of your armrest.

I made a large one, and a 'regular' one. The regular one is enough for my 9 inch coil, but you may like the larger one, especially if you have larger coils.
With my Prusa mk3 it fits perfect and snaps into place. (it only fits one way, so look closely).

If it doesn't fit, don't force it, but print a new one at 101% scale an try that.

Print a spare one to give away to someone you meet in the field with the same detector:)