Presence of Might

Presence of Might is used on leg and head armor to permanently increase stamina, defense and shield block.

Source
Presence of Might is a quest reward from the quest Presence of Might (quest) which starts with Zanza the Restless in Zul'Gurub. To complete the quest, you must turn the following items to Zanza the Restless:
 * 1 Primal Hakkari Idol
 * 1 Punctured Voodoo Doll (warrior)