This ring appears to be a nondescript precious metal band; often, it is sized for the largest finger of a medium humanoid creature, which may fit it to the smallest finger of a large humanoid creature, or on the thick thumbs of a small humanoid creature.
When equipped, if the wearer comes into contact with an effect from any "Ring of X Ring" such as the Ring of Greater Ring or the Ackermannacles, the effect is nullified and the Ring of Unring loses it's magic.
A Ring of Unring can be created by casting counterspell on a ring every day for a month.
AC and HP are inherited from the progenitor ring.
When destroyed, a Ring of Unring deforms into a mobius strip.