This thing is very similar to the TUSH spool holder, only designed to use on top of an ATX power supply.
Just like TUSH it requires to print four pieces of this and you will need four 608 bearings.
Why an ATX PSU with a spool holder on top?
-You can easily find ATX PSU's on otherwise useless old computers, and these are generally a better solution than some crappy Chinese PSU made to power LED's.
-Placing a weight (spool) on top of the 3D printer's frame will cause vibrations on the frame to have lower frequency, but also higher amplitude, which increases Z wobble on the prints, particularly if said weight is offset. Having the spool holder disconnected from the frame is generally a better solution.
The FreeCAD file is included, in case you want to make modifications.