HP printer models using the HP c6614a black and HP 51649 color inkjet cartridges ( * = optional HP c1816 photo cartridge can be used in):

HP Deskjet 610C* / 610CL* (shown at left)
HP Deskjet 612C*
HP Deskjet 630C*
HP Deskjet 632C*
HP Deskjet 640C*
HP Deskjet 642C*
HP Deskjet 648C*
HP Deskjet 656C*

Apollo P-2300U
Apollo P-2350U
Apollo P-2500U*
Apollo P-2500P*
Apollo P-2550P
Apollo P-2600U*
Apollo P-2600P*
Apollo P-2650P