For some of you young-uns that may be a little confused, allow me to clear things up.
You see, way back in the day, digital production presses used a component called a "fuser" to adhere the toner to the paper. It was a replaceable consumable (like toner) that was only good for xxxxx number of pages before it needed to be replaced. As I remember, they were quite expensive.
There were a lot of other reasons why the fuser would need to be replaced such as instances where you needed to switch to a larger sheet size than you normally run, to run envelopes, or, to run a 5th or 6th color. On our iGens, we usually had 3 to 4 extra fusers on hand, each either labeled for a specific use, or, labeled as new or old.
Today's digital presses side-step all those problems because they don't really use "fusers" anymore. They use "fuser-belts", which is an entirely different technology altogether. They don't use oil, they don't need to be replaced after a certain number of pages, or, to run different size stocks, envelops, or extra color stations. On rare occasions, during a service call, the technician may need to replace the fuser belts from normal wear and tear, but it is not a normal occurrence and is covered under your service contract.
i hope you've enjoyed this trip down memory lane and, now, you know what a "fuser" is. Lol