These printers use the CQ121A cartridge:
Click On a Printer to View it's Cartridges
HP Scitex FB-500
HP Scitex FB-500 INDUSTRIAL Printer
HP Scitex FB-550
HP Scitex FB-550 Printer
HP Scitex FB-700 INDUSTRIAL Printer
HP Scitex FB-750 Printer
HP Scitex FB-950 Printer