These printers use the E250A21A cartridge:
Click On a Printer to View it's Cartridges
          Lexmark E 250
          Lexmark E 250 D
          Lexmark E 250 DN
          Lexmark E 350
          Lexmark E 350 D
          Lexmark E 352
          Lexmark E 352 DN
          Lexmark E 450
          Lexmark E 450 DN
          Dell 1720
          Dell 1720 N
          Dell 1720-30PPM
          Dell 1720 DN