Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Rockbound Chestguard Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Rockbound Chestguard suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Rockbound Chestguard is part of the transmog set Leyline Defender's Sunplate Armor (Warrior, Paladin and Death Knight only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 134135 (134129 to 134140) were usually added in the same batch as Rockbound Chestguard: the same quest line, zone, vendor or reward set.
Thick Ironhorn HideID 134129 · Quest · item level 40"High-altitude ironhorn tend to have thicker, more productive coats."
Shaggy Saber HideID 134130 · Quest · item level 40"The sabers of Highmountain tend to have more fur than those found elsewhere."
Bristled Bear SkinID 134131 · Quest · item level 40"Large, durable, and incredibly useful when crafting mail armor."
Calcified WormscaleID 134132 · Quest · item level 40"The scales on the back of the Highmountain worms are notoriously tough."