Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Netherwhisper Gloves Compares
Who It Suits
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Netherwhisper Gloves suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Transmog Sets
Netherwhisper Gloves is part of the transmog set Vestments of the Manasinged (Priest, Mage and Warlock only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 134393 (134388 to 134398) were usually added in the same batch as Netherwhisper Gloves: the same quest line, zone, vendor or reward set.