What do you do if you're given an extra key for a classic game that you've already owned in one form or another for almost 20 years ?
That's right, you pass on the key to someone who doesn't have it yet.

Key should be region free (yay!).

Also, winner should check out this overhaul mod: https://store.steampowered.com/app/397550/Deus_Ex_Revision/
I don't really like the new soundtrack it includes, but the rest of the package is good stuff.