Brainlash

Brainlash is a quality ring with bonuses to Intellect, Stamina and Critical Strike.

Source
This item drops from Sandarr Dunereaver in Zul'Farrak.

In the RPG
Not so much a ring as a wrap designed to completely encase the wearer's index finger, a brainlash is formed of what appears to be a thin sheet of platinum laced with spidery gold webbing. Once slid over the finger, the covering becomes as flexible as cloth, but stays in place until the owner removes it. When a brainlash is first attached, no immediate effect occurs. Over the course of the next day, the wrapping slowly enhances its wearer's intellect by tapping his life force. At the conclusion of the 24-hour period, the bearer's intellect is increased, but his stamina is decreased. Once in this state, the brainlash cannot be removed easily. The wearer must will it to deactivate its power, returning the enhanced mental power to its normal place over the course of another day. At this point the wearer's attributes return to normal and the wrapping slips easily off the finger.