What this item is:

Didn't I tell you it is used to enable the switches in the tao dungeon a few days ago?

Yeah, but I couldn't find where, so I was hoping someone would give me a direct location. ^^;

In the Underground Ruins (through the ventilation pipe thing), you get to see like a prison cell with 4 NPCs inside, you are able to open that prison cell to rescue them but I have no idea what was the purpose for it since I never got to see any quest related stuff with them.

Hmm, tried using at it before, but it didn't do anything. -- I guess I'll have to do it again on hard.

So where did you even get that item?

He looted it on hard mode =P

^ That.

I don't remember which mob dropped it, but I got it from the Tao instance on hard.

random drop either easy or hard.
I just delete it