Burnished Breastplate of Might

Heirloom item
An Heirloom item scales to the level of the character it is being worn on. It should last most classes to level 80 and can be mailed to a person's alternate character if they are on the same account.

Source
This item is sold by the following vendors for :
 * in Dalaran
 * in Dalaran
 * in Dalaran
 * in Stormwind City
 * in Orgrimmar

Once the title has been earned, this item can also be purchased from  in Icecrown for.