This set of 100 o-rings is suitable for Mutoh Drafstation printers. This is the original Mutoh part (number DF-42267). This O-Ring has an inner diameter of 3mm and an outer diameter of 5.4mm.
 
Printer compatibility
Mutoh RJ-900C (Drafstation)
Mutoh RJ-900X (Drafstation)
Mutoh RJ-901C (Drafstation Pro)
Mutoh Valuejet 1304W