What key are you?

From TimelessCalligraphyStudio:

You're the key to handcuffs. You set people free,
or maybe lock them up. You can be sought,
fought over, and valued. Be careful who you let
use you; you can be an instrument of justice or
injustice depending on your choice.

What sort of key are you and what do you unlock?
brought to you by Quizilla