This item is for use with the #GridFinity system by Zach Freedman:
https://www.youtube.com/watch?v=ra_9zU-mnl8
This is a 4 unit wide by 1 unit deep by 1/4 unit high hook up wire spool holder. This is compatible with common wire hookup kits such as: https://www.amazon.ca/CBAZYTM-Stranded-Gauge-Colors-Electrical/dp/B075M8DGYX/
It will work with most common spool sizes, and uses a 6mm rod (as supplied with most kits). There are 6 threading holes at the front.
UPDATE
I added the source file as per request, but it isn't parametric so heads up.
I removed the raised front panel as it was pushing the spools back too far, the holes are in the gridfinity body now.
Contrary to Zach's instructions, I've been printing all my modules with a 0.8 nozzle, which seems to work just fine. This was printed with Black eSun PLA PLA at 75mm speed on an ender 3 pro with 0.8 nozzle and 0.32 layer height without support.