M14 part help

[TomHuytonAirsoft]

Hi, just need to know what part this is, it fell out of my Cyma CM032?? it doesnt have any affect on the gun firing though?

 

 

 

[Samurai]

Isn't this one on the rear part of the gas block / front sight that's inside the body? The front part of the charging handle hits this, when you release it. I remember something like that vaguely.