This can join the two ends of an ethernet cable so you can coil it up, and keep the ends together and protect the clips a bit, especially when stored with piles of other cables.
There is a slight overhang on the top but it seems to print OK anyway.
This model is more or less parametric.
If the plug is too snug, increase slide; or decrease it if it is too loose.
len is the length of the hole beyond the back of the clip.