These cable guides can be clipped with MakerGrid clips (see https://www.printables.com/model/123580-makergrid-base-parts ) onto almost anything in the MakerGrid ecosystem.
There are three different sizes, one for 0-2mm cables (single wires), for 2-4mm cables (such as USB cables) and one for 4-7mm cables (power cords, CAT/Ethernet cables). A fourth type is available for 0-6mm cables, that is also slightly easier to slip cables in and out, but also uses more space.
You can for instance use these in combination with my T-Slot clips (see https://www.printables.com/model/194688-makergrid-clip-for-aluminum-extrusion-t-slot-20x20 ) to manage cables on your 3D printer.
The author hasn't provided the model origin yet.