- the Etemon and SkullGreymon located in the Continent Desert drop them very rarely and only if you reach the ranking top places.
- if you get 100 Desert coins (through some raid daily quests on the Continent desert map), Phantomon will trade you a Desert Ring (it is the same thing as a Quadcore Ring, except it is restricted to Digimon lv65 and above)
- if you get a certain amount of Canyon Light through the Diablomon raid daily quest in the Server Continent Canyon, you can get a Quadcore Ring from Jijimon
Quadcore Necklaces: the Etemon raid located inside the Nanomon Maze (Hard) can drop a quad necklace regardless of your ranking. The chances are very low.