What is this Keurig part from the kpod holder? How does it fit it?

What is this Keurig part from the kpod holder? How does it fit it?

I have removed Keurig K500 Kpod basket holder while cleaning it and now cannot remember where this part fits. Can someone please identify the part , what it does and how it fits the kpod holder . I have tried to install it thinking it would snap into the top of the holder with no success.