Piece from inside printer

[Pita2018]

I was attempting to insert a new toner cartridge when a 8" long, 4" diameter black plastic piece came loose inside the printer.  It has a blue label on it with an illustration of an arrow that suggests you would lift or lower it.  There is the following on the label:  >PP<  RC5 7964.  The interior of the printer is dark and small even with a flashlight/overhead/side lighting.  I can't, for the life of me figure out where it belongs!  I don't know if something broke off of the piece that makes it seem it doesn't fit anywhere. I tried to look up that number to see if there was a replacement part but I can't find it anywhere.   I don't have a lot of free time to figure this out & I learned on a separate HP product that it doesn't have the best customer support.  I have just resorted to using an old printer I still have on hand.  Thoughts about what the part is, why would it pop loose, do I need a replacement, where would I get one?  Whatever? Thanks in advance for input.     

[Valsimot]

Printer model you are referring and a photo of the part?

[Pita2018]

HP Laserjet M209dW   Pics of the piece pasted below, showing different angles of it.  It is hard to show better details because it is all black. That said, it has small "rollers" that look like barbells from 1 angle; and if you press on them, they recess a bit down to the middle of the piece.

The inside of the printer is so confined and dark I can barely get an angle into the space much less see what/how this piece inserts into the printer. 

Thank you for responding to this.    

[Valsimot]

The green peg goes in to the green hole, the red one just lock when you place the whole part inside. 

You have pegs on both sides of the part that cam out, check if they are still present ( not broken or missing) 

The green ones you need to install first and you can do that it you bend the part slightly with your hands in the middle to shorten the distance between two green pegs and install it inside the printer, the red ones will lock in place when you lift the part upwards.