Royal Sending Stone
One of a matched pair of stones, each carved with the arms of Khanduras. King Leoric gave this one to his son, Prince Albrecht, to keep him safe, and kept the other. You don’t know which this is, but it was covered in blood.
Wondrous item, uncommon.
Sending. While you touch this stone, you can cast Sending from it. The target is the bearer of the other stone. If no creature bears the other stone, you know that fact as soon as you use the stone, and you don’t cast the spell.
Once Sending is cast using a stone, that stone can’t be used again until the next dawn. If one of the stones in the pair is destroyed, the other one becomes nonmagical.
Homebrew rules:
Two-way communication. Functionally identical to Sending Stones, except each stone can be used once per day.