This is a simple end cap, covers the bare aluminium profile. And offers protection for your walls (If you're like me and constantly bang the ends of the track while lifting it into position)
My original one broke, as I took it off incorrectly. You can print this lying flat, it is arguably weaker. But it is not weight bearing and hopefully does not need to be removed again.
My original one was a rectangular shape, but I thought I'd have a go and match the contour of my track.
The author marked this model as their own original creation.