amulet of vitality

amulet created by the elder of the wood. 

once per day, the wearer of the amulet can store up to 10 hit points in the amulet using their hit die. as a bonus action, a character can release the energy stored within the amulet , gaining the stored amount of hit points as temporary hit points. any unused hit points stored within the amulet are lost upon completing a long rest.

Notes: Bonus: Temporary Hit Points