Flawless Arcanite Rifle

Source
The Flawless Arcanite Rifle is crafted by Engineers with a skill level of 300.

The components are:
 * 10 Arcanite Bar
 * 2 Thorium Tube
 * 2 Essence of Fire
 * 2 Essence of Earth
 * 2 Azerothian Diamond
 * 2 Enchanted Leather

The drops off Mossflayer Shadowhunter in the Eastern Plaguelands.