This is a Sharpie holder that fits a standard marker and one or two 10 mm x 2 mm magnets. The marker will fit loosely around the bottom/middle, or a more snug fit near the cap, depending on if you want to take the marker out of the holder or leave it attached.
The magnet holes are sized to be a tight fit, so adjust for your machine's tolerances.
I've also added a version for the jumbo, chisel-tip Sharpie.
The author marked this model as their own original creation.