I am not sure what the black piece is. Is it like a foam or something? What's it made of?
I just got my kit in and I don't have anything like that. All I have that looks like that is the rubber piece that holds the tubes in place. The tape is just extra for holding down the wires if you want to out of the way of the fan.
I'm wondering if it's a piece of foam that broke away from the packaging or something.
Regardless, it doesn't look like it would be used in this kit at all. I don't see anywhere where this would be used.