Bloodvine Lens

The Bloodvine Lens is a leather eyepiece that provides bonuses to critical hit chance as well as better stealth detection. You must have an Engineering skill of 300 to use the Lens.

Source
The Bloodvine Lens is crafted by Engineers with a skill level of 300.

The recipe for this item is taught by, which is sold by Rin'wosho the Trader in Stranglethorn Vale. You must have reputation with the Zandalar Tribe to purchase this schematic.