Tier 18 is the armor set associated with Patch 6.2.0. It is obtained from Hellfire Citadel. All the tokens can be used immediately to gain the set item associated with the token.
Unlike tier tokens used since The Burning Crusade, the item created can be used for any specialization since secondary attributes specific to certain roles (hit, expertise, dodge and parry) on gear has been removed with Warlords of Draenor. Attributes like bonus armor (for tanks) and spirit (for healers) can thus only be attained from necklaces, cloaks, bracers, belts, boots, rings and trinkets.