These printers use the C544X2KG (High Yield) cartridge:
Click On a Printer to View it's Cartridges
          Lexmark C 540 DW
          Lexmark C 544
          Lexmark C 544 DN
          Lexmark C 544 DTN
          Lexmark C 544 DW
          Lexmark C 544 N
          Lexmark X 544
          Lexmark X 544 DN
          Lexmark X 544 DTN
          Lexmark X 544 DW
          Lexmark X 544 N
          Lexmark X 548 DE
          Lexmark X 548 DTE