These printers use the X651H21A cartridge:
Lexmark X 651
Lexmark X 651 DE MFP
Lexmark X 651 DE
Lexmark X 652 DE MFP
Lexmark X 652 DE
Lexmark X 654
Lexmark X 654 DE MFP
Lexmark X 654 DE
Lexmark X 654 E
Lexmark X 656
Lexmark X 656 DE MFP
Lexmark X 656 DTE MFP
Lexmark X 656 DE
Lexmark X 656 DTE
Lexmark X 656 E
Lexmark X 658
Lexmark X 658 DE MFP
Lexmark X 658 DFE MFP
Lexmark X 658 DME MFP
Lexmark X 658 DTE MFP
Lexmark X 658 DTFE MFP
Lexmark X 658 DTME MFP
Lexmark X 658 DE
Lexmark X 658 DFE
Lexmark X 658 DME
Lexmark X 658 DTE
Lexmark X 658 DTFE
Lexmark X 658 DTME
Lexmark X 658 E
Lexmark XS 651 DE
Lexmark XS 654 MFP
Lexmark XS 658 DME