Summary

It may be hard to figure out what's going on in the photo, but these are clips that attach to bed rails and hold wires (or other things, I suppose) either parallel or perpendicular to the rails, depending on which clip you select. The long part of the clip goes above the rail, and they fit snugly enough not to wiggle around much.

Handy for keeping wires up and off the ground so they're not shoved around by your robotic vacuum.

Of course, if your bedrails aren't the precise dimensions of mine, you'll need to measure them carefully and update the SCAD file. Uses the BOSL2 libraries, so unfortunately, doesn't seem to work with the Customizer.