Guardian Talisman

The Guardian Talisman is a trinket that gives a chance of increasing the wearer's armor when hit in combat. If you've done the quest chain once, and have a basic understanding of the chain, this can be one of the earliest trinkets a non-engineer character can obtain.

Source
The Guardian Talisman is a quest reward from the following quests:
 * Into The Temple of Atal'Hakkar
 * The Temple of Atal'Hakkar (quest)