In The Burning Crusade it is item level 115 and requires level 70. In Wrath of the Lich King it is item level 251 and requires level 80. In MoP Classic it is item level 115 and requires level 70.
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Glider's Greaves Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Glider's Greaves suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Glider's Greaves is part of the transmog set Warbringer Armor (Warrior only). The other 15 pieces:
Blizzard numbers items as they are created, so the named items next to ID 30683 (30678 to 30688) were usually added in the same batch as Glider's Greaves: the same quest line, zone, vendor or reward set.