Part of the Darkmantle Armor set:

The set gives these bonuses as more pieces are worn: 2: +8 All Resistances. 3: Restores 15 health per 5 sec. 4: Chance on melee attack to restore 20 Energy. 5: When struck in combat has a 5% chance to remove a Snare effect from yourself. Can only occur once every 60 sec. 6: +40 Attack Power. Set Details | All Sets