Lost Notes of the Crimson Regalia

Arcanist's Circlet

Wondrous Item Very Rare (this item requires attunement)

This headpiece is made out of silver, with three round gems affixed on it.   While attuned to this circlet, you regain an extra spell slot automatically upon spending your last 1st, 2nd and 3rd spell slot for each level.   Also, you get advantage when you roll for saves to maintain concentration on spells.