I've been completing the Monk Quests. I had Monk from 1.0, so when you have the lvl 45 Monk Quest you receive 4 pieces of the AF. At this point, i had the full AF already, so when i opened a box, i received a second pair of "Temple Gaskings". I didn't get the other pieces because i had them in my inventory already, but i got a second pair of "Temple Gaskings" because my original piece was in one of my retainers...

It's kinda annoying because you can't discard or sell this duplicate