Citizen AH37901-0 (AH379010) compatible black ribbon.
High quality compatible ribbon.
Not manufactured by Citizen:
GSX-130 (GSX130)
GSX-140 (GSX140)
GSX-140+ (GSX140+)
GSX-220/CT (GSX220/CT)
GSX-230 (GSX230)
GSX-240 (GSX240)
GSX-340 (GSX340)
GSX-540 (GSX540)