These printers use the 51640 cartridge:
Click On a Printer to View it's Cartridges
          HP CopyJet
          HP CopyJet M
          HP DesignJet 230
          HP DesignJet 230 D-Size
          HP DesignJet 230 E-Size
          HP DesignJet 250
          HP DesignJet 250 C
          HP DesignJet 250 C D-Size
          HP DesignJet 250 C E-Size
          HP DesignJet 330
          HP DesignJet 330 D-Size
          HP DesignJet 330 E-Size
          HP DesignJet 350 C
          HP DesignJet 350 C D-Size
          HP DesignJet 350 C E-Size
          HP DesignJet 430
          HP DesignJet 450 C
          HP DesignJet 455 C
          HP DesignJet 455 CA
          HP DesignJet 488 C
          HP DesignJet 488 CA (24inch)
          HP DesignJet 488 CA (36inch)
          HP DesignJet 488 CA Wide Format
          HP DesignJet 650
          HP DesignJet 650 C
          HP DesignJet 650 C PS
          HP DesignJet 650 CD
          HP DesignJet 650 CE
          HP DeskJet 1200 C-PS
          Encad CadJet
          Encad Cadet II
          Encad Cadjet II (36 inch)
          Encad Cadjet III
          Newgen Vista Color Plotter
          Riso-Corporation RJ 1100