As a Bonus action you can use this ring to cast one of the Tiamat´s breath, when you do you can´t do it again until 24 h pass.

+ Black Dragon Head: Tiamat breathes acid in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 27 Dexterity saving throw, taking 15d8 acid damage on a failed save, or half as much damage on a successful one.

+ Blue Dragon Head: Tiamat breathes lightning in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 27 Dexterity saving throw, taking 15d8 lightning damage on a failed save, or half as much damage on a successful one.

+ Green Dragon Head: Tiamat breathes poisonous gas in a 90-foot cone. Each creature in that area must make a DC 27 Constitution saving throw, taking 15d8 poison damage on a failed save, or half as much damage on a successful one.

+ Red Dragon Head: Tiamat breathes fire in a 90-foot cone. Each creature in that area must make a DC 27 Dexterity saving throw, taking 15d8 fire damage on a failed save, or half as much damage on a successful one.

+ White Dragon Head: Tiamat breathes an icy blast in a 90-foot cone. Each creature in that area must make a DC 27 Dexterity saving throw, taking  15d8 cold damage on a failed save, or half as much damage on a successful one.