It looks to be from some kind of protective collar.
Royal Avenue Electrium Z It converts Z-Power into crystals that upgrade Electric-type moves to Electric-type Z-Moves.
Have Glalie hold it, and this stone will enable it to Mega Evolve during battle.
This stiff, heavy brace helps Pokémon grow strong but cuts Speed in battle.Yellow Nectar A flower nectar obtained at Melemele Meadow.Blush Mountain, Heahea City Luxury Ball A particularly comfortable igre poker aparat veca manja Poké Ball that makes a wild Pokémon quickly grow friendlier after being caught.During a contest, it raises the Clever aspect of the Pokémon holding.Heahea City Ride Pager By entering certain numbers on this pager, you can summon Ride Pokémon in an instant.Konikoni City Wild Encounter Bagon, Shelgon, Salamence, Druddigon Dragon Gem A gem with a draconic essence.If a Pokémon holds one, it can recover from being frozen on its own in battle.Route 1 Shop Royal Avenue Yellow Scarf An item to be held by a Pokémon.Its pink flesh is sweet when eaten.Route 10 Rabuta Berry Used to make Pokéblocks that will enhance your Cleverness, this Berry is rare in other regions.Wild Encounter Cottonee, Petilil Adamant Orb A brightly gleaming orb to be held by Dialga.Buy at Pokemon Center.Salac Berry A Berry to be consumed by Pokémon.Lush Jungle Ilima's Normalium Z The Normalium Z you were entrusted with by Ilima.Voices can be heard from it occasionally.
Durin Berry Used to make Pokéblocks that will enhance your Cleverness, this Berry is rare in other regions.
Ancient Poni Path, Heahea City, Lush Jungle Shop Konikoni City Revive A medicine that can revive fainted Pokémon.

Heahea City, Mount Hokulani Love Ball A Poké Ball that works best when catching a Pokémon that is of the opposite gender of your Pokémon.
Shop Battle Tree Garchompite One of a variety of mysterious Mega Stones.