LD Compatible Printer Ribbon Cartridge Replacement for Okidata 42377801 (Black, 5-Pack) Page Yield: 7,500,000 characters per cartridge | Shelf Life: 24-36 months per cartridge We offer lightning fast shipping on all printing supply and inkjet photo paper orders The use of LD replacement ink and toner cartridges does not void your printers warranty All LD branded products are backed by a 100% satisfaction and LIFETIME guarantee For use in the following printers:OKI MICROLINE:420, 420 n, 421, 421 n, 490, 490 n, 491, 491 n, 720, 721, 790, 791