Pattern: Assassin's Chestplate

Source
This item is sold by the following vendors for :
 * in Ironforge
 * in The Exodar
 * in Stormwind City
 * in Undercity
 * in Thunder Bluff
 * in Twilight Highlands
 * in Darnassus
 * in Orgrimmar
 * in Twilight Highlands
 * in Silvermoon City