TM M4A1, identify this piece (Not sure where it goes)
 

When I took apart and reassembled my M4, I found this piece on my desk. I am unsure of where it goes or if its important. If anyone has any idea what it is or where it goes it'll be a lot of help.

Its a small donut like ring with 3 prongs pointing towards the center, I attached a picture of it below.

Thanks again

Holds the hopup gears on. Check your hopup unit.

Humm it seems like i already have one there? Anywhere else this fits in?

Take it out and check the other side, it's probably from the pivot pin.

This part right here??
Thanks for all your help harleyB

No, it's for the other one, just to the left in the picture. Sorry, I guess pivot pin was the wrong term. I'm tired, sue me =P

haha
I got it
thanks for all your help :) appreicate it
I hate not knowing where a part goes :( first time taking apart my m4

Don't sweat it.

guys are quick here and help out lots. just be glad it was not the spring for the tappet plate. or and other small spring in that case.