Ring of Incredible Strength (5e Equipment)
From D&D Wiki
Ring, uncommon or rare (requires attunement)
While you wear the uncommon version of this ring, your Strength score gets set to 19. While you wear the rare version of this ring, your Strength score gets set to 21, and you can choose to use a weapon with the two handed property with one hand (only affects one weapon at a time) or to use a weapon with the heavy property as if it didn't have that property.