Tier 3

Tier 3 is a type of armor set. Each set consists of 9 pieces. The items can no longer be acquired, as certain tokens from Naxxramas bosses were needed, which no longer drop as of patch 3.0.2.

Location
The items that form these sets are quest rewards. The quests require, among other things, token drops from bosses in Naxxramas. The only exception are the rings, which drop directly from Kel'Thuzad in Naxxramas.

The tokens for the following items were found on the first two bosses of a specific wing in Naxxramas as well as on Gluth: The tokens for the following items could be found on the endboss of a specific wing in Naxxramas:
 * The token for the belt of each set dropped from bosses in the plague wing: Noth the Plaguebringer and Heigan the Unclean,
 * the token for the wristpiece of each set dropped from bosses in the spider wing: Anub'Rekhan and Grand Widow Faerlina,
 * the token for the boots of each set dropped from bosses in the deathknight wing: Instructor Razuvious and Gothik the Harvester and
 * the token for the shoulderpiece of each set dropped from bosses in the abomination wing: Patchwerk and Grobbulus.
 * The token for the headpiece of each set dropped from Thaddius in the abomination wing,
 * the token for the pants of each set dropped from Loatheb in the plague wing,
 * the token for the gloves of each set dropped from Maexxna in the spider wing and
 * the token for the chest piece of each set dropped from The Four Horsemen in the deathknight wing,

The following classes share tokens:
 * Paladin, Hunter, Shaman, Druid
 * Priest, Mage, Warlock
 * Warrior, Rogue