These printers use the 4423C001 cartridge:
Click On a Printer to View it's Cartridges
          Canon MAXIFY GX-3020
          Canon MAXIFY GX-4020
          Canon MAXIFY GX-5020
          Canon MAXIFY GX-5520 X
          Canon MAXIFY GX-5550
          Canon MAXIFY GX-6021
          Canon MAXIFY GX-6040
          Canon MAXIFY GX-7020 X
          Canon MAXIFY GX-7021
          Canon MAXIFY GX-7040