Technically the riser is the wide bar that contains the heating elements that “fuses”, or irons, the toner into a permanent attachment to the paper
warning major ad supported page~what is a riser~Generically it’s the entire assembly that contains the riser, the feed rollers, the toner drum, etc. generic term comes from the common ability to remove that whole assembly with just a few screws.
Other large generic pieces are the power assembly, the motor assembly, the page feed assembly.
and on commercial machines the post processing assembly with the staplers, folders, etc.
Those machines are heavy.
I’d mind ebay parts values though. The thing that keeps me coming back for them on a rare occasion.
The toner drum is the lightest item in the machine and can fetch $50+!
mint condition pickup rollers (the bar of wheels closest to the feed tray) get expensive too. Even the trays can fetch cash.