You can gain the benefit of three magic rings at once.
Prerequisites: Wisdom 13
When wearing 3 magic rings (two on one hand), you are able to channel the power from one of those rings to another part of your body. When using this feat, a body slot other than your finger slots is considered filled for the purposes of magic items. Your ring is still damaged in the normal order if you roll a 1 on a saving throw.
Normal: You can only gain the benefit of up to 2 magic rings at the same time.
Does this exist elsewhere? I don’t believe so.