Shifting Naaru Sliver

Shifting Naaru Sliver is an epic trinket for DPS casters.

Source
This item drops from M'uru in Sunwell Plateau.

Effective Damage
On top of the quite substantial 54 haste rating already offered by this trinket, it has a very powerful on-use effect, which essentially grants an additional: 320 * (15 / 90) = 53.3 +damage In stationary fights, provided it is activated upon every cooldown.