The SAM4s ER-5200M uses 2.25" Thermal paper rolls and does not require an ink ribbon. The ER-5200M has both a receipt and journal (Audit) printer. Both printers use the same paper and it must be thermal. This register can accommodate a full size paper roll so don't use the rolls designed for credit card terminals because you will be changing the paper all the time. Of course because this machine uses thermal paper no ink ribbon or roller is required. Many people also have a kitchen printer attached to the 5200M and if that is your case most likely the kitchen printer will use a different paper roll and possibly an ink ribbon.
Keep paper in your cash register at all times. Operating without paper could damage the printer. Even if you don't issue a receipt just turn it off and issue on demand but don't remove the paper.