Lexmark 0064016HE High Yield Return Program Print Cartridge Black. For use with Lexmark T640, T640n, T640dn, T640dtn, T642, T642n, T642tn, T642dtn and T644, T644n, T644tn, T644dtn printers. Page yield 21,000.Compatible Printers: Lexmark T 642 DN, Unisys UDS 540-N 11, Lexmark Optra T 640 N, Lexmark Optra T 640, Lexmark T 642 TN, Lexmark T 642, Lexmark T 642 N, Lexmark T 642 DTN, Lexmark T 640 DTN, Lexmark Optra T 640 DTN, Lexmark T 640 DN, Lexmark T 640 N, Lexmark Optra T 640 DN, Lexmark Optra T 642 DTN, Lexmark Optra T 642 N, Lexmark Optra T 642, Lexmark T 640, Lexmark Optra T 642 TN, Lexmark Optra T 642 DN, Lexmark T 640 TN, Lexmark Optra T 640 TN