Insignia of the Alliance (Mage)

Insignia of the Alliance is a quality PvP reward that removes all movement impairing effects but does not prevent them from being reapplied. Usable even if the effect would normally prevent trinket use. This item is popular for level 19 twinks for use in Warsong Gulch, where being able to break rooting can bring a victory.

Source
This PvP reward item can be purchased from in Champions' Hall in Stormwind for.