- Serpent-Coil Braid
- Binds when picked up
- Unique
- Trinket
- Classes: Mage
- Requires Level 70
- Item Level 128
- Equip: Improves hit rating by 12.
Equip: Improves critical strike rating by 30.
Equip: You gain 25% more mana when you use a mana gem. In addition, using a mana gem grants you 225 spell power for 15 seconds. - Sell Price: 7
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Serpent-Coil Braid is an epic trinket for mages.
Source
This item drops from Morogrim Tidewalker in Serpentshrine Cavern. The use of this trinket combined with a 
[Mana Emerald] will restore approximately 3000 mana back to the caster.
Effective Damage
The effective +damage from this trinket is difficult to calculate, as it is not always prudent to use Mana Gems the moment they come off cooldown. Assuming one does however, this item adds an additional
225 * (15 / 120) = 28.125 +damage
It is important to note however, that the real benefit of this trinket comes from the additional ~3000 mana gained from using a Mana Emerald - which can add quite a substantial amount of DPS for an Arcane Mage who utilises heavy Arcane Blast spam.