Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Ferroleather Spaulders Compares
Who It Suits
Leather is the armor type Demon Hunter, Druid, Monk and Rogue wear. With Agility or Intellect, Ferroleather Spaulders suits Assassination, Outlaw and Subtlety Rogue; Brewmaster, Mistweaver and Windwalker Monk; Balance, Feral, Guardian and Restoration Druid; Havoc, Vengeance and Devourer Demon Hunter.
Transmog Sets
Ferroleather Spaulders is part of the transmog set Ironpelt Garb (Rogue, Monk, Druid and Demon Hunter only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 139629 (139624 to 139634) were usually added in the same batch as Ferroleather Spaulders: the same quest line, zone, vendor or reward set.
Shard of DarknessID 139624 · Miscellaneous"Dark smoke obscures the inside of the crystal, but faint screams can be heard from somewhere deep within."