The Lexmark 12026XW is the original Lexmark photoconductor kit (imaging drum unit) for the Lexmark E120 and E120n monochrome laser printers. In these printers the toner cartridge and the photoconductor are separate consumables: the toner cartridge is replaced more often, while this drum unit, rated for up to about 25,000 pages, transfers the toner image onto the paper over a much longer life. Replacing the photoconductor when the printer reports it worn restores sharp, even print quality and prevents streaks, grey background and repeating marks caused by a worn drum. The kit contains one black photoconductor unit, and it is designed and manufactured by Lexmark for these printers. It is a good buy for offices and schools still running E120-series printers who want to keep them in service with genuine parts. Note that actual drum life depends on print job length and environment. Toner cartridges for the E120 are sold separately.