OEM parts are the only "no-grief, hassle-free" solution to printer maintenance! After-market parts may save you money but you'll pay the difference in time (and may become a full-time Printer Technician in the process). If you have time but not money, go with after-market kits. For us, time is more than money so OEM is the only way to go.
This is a complete kit with all rollers needed for the M681 with 4 trays, very well packed and organized. It has instruction booklets for each type of roller, with pictures to show how to replace each one. There are tools included that help with removing the old rollers and properly seating the new ones. I installed two of these in the past week, the second one took less than 1/2 hour to complete.