Who It Suits
Leather is the armor type Demon Hunter, Druid, Monk and Rogue wear. With Agility or Intellect, Prime Wraith's Jerkin 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
Prime Wraith's Jerkin is part of the transmog set Guile of Maldraxxus (Rogue, Monk, Druid and Demon Hunter only), which the Appearances collection lists in 2 versions. The other 8 pieces:
Built from the World of Warcraft client build files and recorded Auction House snapshots.