Warp-Scarab Brooch

Source
This item drops from Nexus-Prince Shaffar in the Mana-Tombs of Auchindoun on Heroic mode.

Effective Spell Power
Assuming this trinket were activated every cooldown, it would grant an effective: 150 * 20 / 120 = 150 * 1 / 6 = 150 / 6 = 25 Spell Power