Where can I buy the clip that holds the screen down?

Theres a clip that goes on the top of the screen of the 4th generation ipod touch which holds it down. I dont have it anymore for whatever reason. Does anyone know where I can buy these. Its pretty essential to keeping the screen down I believe. Its the clip that gets glued to the under part of the top screen and has the whole in it.

Anyone know of any places to get it?

Anyone have any idea?