Windforged Leggings

Windforged Leggings is a rare level legging that is craftable and wearable only by Blacksmiths with the Armorsmithing specialty.

Source
This item is crafted by Blacksmiths with a skill level of 260 who also have the Armorsmith specialty.

The plans can be learned from the Armorsmith trainers:
 * in Ironforge
 * in Orgrimmar