These printers use the C544X1CG cartridge:

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