Z-Ring

Z-Rings are bracelets from the Alola region. They can either be obtained from Island Kahunas or ToysRUs (next to their stock of Yokai watches).

History
Prior to the series, Kiawe obtained a Z-Ring from an Island Kahuna, as well as his Firium Z Z-Crystal.

Kiawe used his Z-Ring in "The Milf, the Mime and the Maniac" when he fought Team Skull and their Pokemon. Some time later, Ash bought a Z-Ring from ToysRUs.

In "For a God's Sake", Ash shows off his Z-Ring to his new classmates, much to Kiawe's dismay as he takes the rings and Z-Moves very seriously. Later on that day, Tapu Koko appears and challenges Ash to use his Z-Ring in a battle with him and they manage to use the Electrium Z Z-Move.

Uses
Z-Rings are used by trainers on their Island challenges to strengthen their Pokemon's moves. There is a Z-Crystal for every type.

Firium Z
Z- Move: Inferno Overdrive

User(s): Kiawe

First Use: "The Milf, the Mime and the Maniac"

Electirum Z
Z-Move: Gigavolt Havok

User(s): Ash / Tapu Koko (demonstration)

First Use: "For a God's Sake"