Don Rodrigo's Band

Don Rodrigo's Band is a ring for cloth casters that gives them a bonus to stamina, chance to critical strike with spells, as well as lowering the resistances of the victim. While it would be ideal for Balance-spec druids and Elemental-spec shamans, it is class-restricted to Mage, Priest or Warlock.

Source
Don Rodrigo's Band is sold for by one of the Supply Officers for Alterac Valley:
 * Gaelden Hammersmith in Alterac Valley
 * Thanthaldis Snowgleam in Alterac Mountains
 * Grunnda Wolfheart in Alterac Valley
 * Jekyll Flandring in Alterac Mountains