What is this part? Where do I have to place it?

Hey Community,
I need your help. I opened my PF2 this evening because I needed to clean it from dust. When I removed the display modul this white soft rubber part came out of the core modul. I never noticed this before, so I dont have an idea where to put it in again? Can you please help me? Discribe the position or if possible send me a picture. :smiley:
I am really thankfull for your help!
Greetings from Germany

We’ve been there, done that :wink: