it's the 11th doctor's sonic screwdriver
It unlocks any lock (not deadlocked of made of wood) interfaces with almost any machine or electronics, and can even emit frequencies that can stun almost any creature in the universe for a few minutes.
It never kills anything, since the doctor is cool like that and doesn't ever really kill anything, though he'll set things up so that the bad guy will end up destroying himself if he doesn't stop killing the humans or whatever he's doing.
I guess you could consider it the "crutch" of the dr who series since it does whatever they need some random thing to do.
Mabinogi Status