Mirror of Aule

The Mithril Mirror of Aule was an aritfact of the Dwarfs. It was a mirror shield that added +100 DB, Constant Reversal True, +80 RR, could see through any and all illusions, and gave a +20 bonus to all stats.

The mirror was worn on the back of Naug II, he didn't need to use it as a shield for it to confer all the abilities listed upon him.