Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Heroes' Earthshatter Chestguard Compares
Who It Suits
Mail is the armor type Evoker, Hunter and Shaman wear. With Agility or Intellect, Heroes' Earthshatter Chestguard suits Beast Mastery, Marksmanship and Survival Hunter; Elemental, Enhancement and Restoration Shaman; Devastation, Preservation and Augmentation Evoker.
Transmog Sets
Heroes' Earthshatter Chestguard is part of the transmog set Heroes' Earthshatter Regalia (Shaman only). The other 16 pieces:
Items Numbered Next to Heroes' Earthshatter Chestguard
Blizzard numbers items as they are created, so the named items next to ID 39597 (39592 to 39603) were usually added in the same batch as Heroes' Earthshatter Chestguard: the same quest line, zone, vendor or reward set.