A genuine OKI Black Toner Cartridge (44992401) installed in your OKI laser printer ensures high quality print output and great reliability. When you see a Toner Low message on your printer's display, make sure to order a replacement cartridge as soon as possible. Install it when you see Toner Empty displayed on the screen and continue printing straight away. This standard yield toner cartridge is packed with enough black toner to print 1,500 pages and is designed for B401, MB441 and MB451 printers.