DuPont : a cromulent connector cover - simpler, smaller, better, faster, in all sizes.

To prevent jumper wires with the ubiquitous 0.1" DuPont connectors from inadvertently being pulled out. Fast and simple to print, for 1 to 8 connections,  in both standard lengths.

Print at 0.2 mm layer height, without supports or brims, in PLA or PETG; the live hinge flexure is long enough to work well even when using the slightly more brittle PLA. Ensure that the fill pattern on the first layer crosses the flexure at right angles to the bending (hinge) line, for optimal strength and durability. I like using the Concentric fill pattern on the bottom layer, which does this, and looks pretty to boot.

The 2.54 mm (0.1") pitch DuPont jumper connectors seem to come with body lengths of either 12 mm or 14 mm, therefore versions were prepared catering for both. The monolithic nature of the design also allows for some independent scaling, if needed. For example, you can scale the length by a few percent, while leaving the other two dimensions unchanged, if you desire to cater for a slightly longer or shorter body, or you can scale the width and height, leaving the length, if you want to make the connectors fit inside the cover a bit more tightly (or loosely). Such adjustments, within generous limits, should not mess up the articulation of either the live hinge or the latching mechanism, so feel free to deform to your heart's content.

Orient the connectors inside the cover to ensure the probe points are on the side where they are accessible via the slots, if you want to be able to measure with a DMM or oscilloscope, or the other way round, to cover them if you want to ensure proper isolation.