KINTO BONBO anneau en silicone, lot de 2

These rings are decent at keeping the lid on, about half the time the cup is dropped even from counter height the lid does not come off. For something that is so thin and relies mostly on friction I would say it's acceptable. Make sure to remove and let the ring dry as frequently as possible as the one I had seemed to grow mold very easily, but it was also easy to clean.