Acorn of Bethaag

Hanging from a delicate chain is an acorn made of fine platinum.  Inscribed upon it are two overlapping rings that encircle the body, just below the crown. When attuned to the acorn, it grants the wearer a fragment of Her Wisdom. While wearing this amulet, you can maintain concentration on an additional spell, to a maximum of two spells simultaneously. While concentrating on more than one spell, you have disadvantage on Constitution saving throws to maintain the spells, and failing the saving throw ends all spells.

Notes: Druid, Cleric, Wizard, or Sorcerer.