This quest is not available in game.
Bring a Lightforge Belt and a set of Lightforge Gauntlets to Deliana in Ironforge.
You kept your word and brought the device built by Mux. I believe a reward is in order if I'm to keep you interested in saving my skin. Bring me the belt and set of gauntlets that you wish to upgrade. I promise the ones I give you in return will be far superior.