You will be amazed with Lexmark's Extra Long Life Cartridges. The Extra Long Life Cartridge offers you an impressive performance that simply can't be ignored.This cartridge is designed for HP LaserJet IIISi, 4Si, 4SiMX, Canon EPN, LBP NX/NX600, DEC Printserver 17/600, Genicom 9170, ISI 7817, QMS 1725/SLS/E Print Systems, Talaris 1794 Printstation, 17946FT Imagestation.