Periapt of Wound Closure

Source: D&D 5.2 SRD Magic Items

Wondrous Item, Uncommon (Requires Attunement)

While wearing this pendant, you gain the following benefits.

Life Preservation. Whenever you make a Death Saving Throw, you can change a roll of 9 or lower to a 10, turning a failed save into a successful one.

Natural Healing Boost. Whenever you roll a Hit Point Die to regain Hit Points, double the number of Hit Points it restores.