Thanks for everyones imput, I am sure it fell from the firearm, I am positive it is a S&W part since it is stamped like the rest of the trigger parts.

I was hoping to have a Sigma expert give me some imput as to where it goes, I am well educated on firearms and take all the steps necessary not to have this problem occure, however these things happen and I am not going to leave it alone until I figure out where it goes.

As for all of the guesses thaks for trying.