Anti-loss ring for rubber bumpers, used in motorbike top case racks (Givi)

You might recognize this, if you're an owner of a motorbike with a luggage rack... :-)

I've frequently lost those small rubber bumpers intended for the top case, from the luggage rack of my motorbike. It's a Givi rack and it's perfect ... apart from the holes with which the rubber bumpers are held in place: these are produced just to large & they hardly clamp the rubber bumpers at all.

So, I figured to do something about it & these 3D printed anti-loss rings are doing the job just fine.