Engrave Belt - Missile Barrage

Engrave your belt with the Missile Barrage rune: Gives your Arcane Blast spell a 40% chance, and your Fireball, Frostbolt, and Frostfire Bolt spells a 20% chance to reduce the channeled duration of your next Arcane Missiles spell by 50%, reduce the Mana cost by 100%, and missiles fire every 0.5 sec.