Valve body question

[98JSims41]

I pulled all my valves out and was cleaning the valve body when this fell out and im not really sure what it is or does. I cant find it in the manual so if anyone does know it would really help me out

 

[Steve93Talon]

Skip to the 4:50 point, if you are using a shift kit you don't put it back in. Otherwise, it goes where he puts the ball.

https://www.youtube.com/watch?v=5P62nEXiOjM

 

[98JSims41]

Thank you! ive been staring at it for hours haha
but i did just find a pdf manual and that piece is called n-d plate(for anyone else that loses its place)