Lol. I expected to get more entertaining responses to be honest.
It is a shortened slide cover plate which is actually an armorer diagnostic tool for checking the engagement of the striker lug to the trigger bar drop safety.
I don't need No stinking signature.
I believe there are more instances of the abridgment of the freedom of the people by gradual and silent encroachments of those in power, than by violent and sudden usurpations .. James Madison