This is a tool holder for the Elegoo Neptune 4 Pro (and probably the Neptune 4).

The printer comes with the code for a tool holder but this toolholder a) does not include space for the steel roller tension adjustment tool and b) is attached to the X gantry, putting more weight on one side of it (probably nit picking here...).

This tool holder has space for the roller tool and clips on to the top of the leg. I also included space for a marker.

I printed it in PLA, the clip holding the front of the holder needs to be strong so I printed with 5 walls, to make sure it was solid. The rest can be at low % infill.

The clearance between the clip and the hole in the bracket holding the top of the Z screw is tight so I include a clip test STL, for those who want to test before printing the whole thing.

I will update it as I get comments. :-)

v1.1: I modified the clip holder to tilt them away from the Z axis screw.
v1.2: I made the all key holes round and all 0.75 mm larger than the tool outer diameter, to make them more reliably large enough.
v2.0: I redid it to let the tools clear the X axis bracket when the Z is at its highest.