Ring, rare
These braided mithril-and-jade rings are always created in pairs. While wearing one of these rings, you can use an action to instantly learn the following information about the creature wearing the other ring:
- Their current hit points and status (alive, unconscious, or deceased).
- Any conditions or spells currently affecting them.
- Their current emotional state (happy, frightened, etc.).
- The current straight-line distance to them. If the wearer is on another plane, you learn that, though you can’t discern which plane they’re on.
-Mordenkainens Tome of Marvelous Magic II