Netherweave Robe

Netherweave Robe is a part of the armor set, Netherweave Vestments. The pattern may be purchased in a limited supply from the following NPCs at a cost of :
 * in The Exodar
 * in Silvermoon City
 * in Shattrath City

Source
Netherweave Robe is crafted by Tailors with a skill level of 340.