A USB or other cable wrap, with a slider to keep the cable tidy. The base and top cap are printed without supports and are joined by CA glue, just a bit, along the surfaces where the two parts meet.
I've included the Fusion file which is setup with user parameters so you can generate whatever size you want. There are two versions that I've put into a .3MF file here, the 100_22_20 model seems about right for 3 meter cables, and the 100_15_10 is for 1 meter cables. Both of the included .3MF files here are setup using standard print settings for a MK3s printing in PLA.
The author hasn't provided the model origin yet.