UR Gears includes "Artifacts" and "Gear Suit".
Besides of the better stats than SSR gear, UR gear also give addtional passive skill and benifits to the heroes. UR Gear details can be looked up in the Codex.
Exclusive Weapon of each hero. Grant additional passive skills. Obtainable from Shop, and Gear Summon.
Gear Suits are available for each class. Give additional benefits when equipped with more pieces of the same Suits. Obtainable from Gear Summon and Drop from Adventure > Chapter 9.