These printers use the 51640C cartridge:

HP Color Copier 210

HP Color Copier 210 LX

HP CopyJet

HP CopyJet M

HP DesignJet 230

HP DesignJet 330

HP DesignJet 430

HP DesignJet 650

HP DeskJet 1200 C

HP DeskJet 1200 C-PS

HP DeskJet 1600 C

HP DeskJet 1600 CM

HP DeskJet 1600 CN

Riso-Corporation RJ 1100