The HP 90X LaserJet High-Yield Black Toner Cartridge is a pack of 2 cartridges designed for high-volume printing. Compatible with various HP LaserJet printers, including the M602dn, M602n, M602x, and M603dn models, this toner cartridge ensures crisp and professional black prints using laser print technology. With a higher yield than standard cartridges, this product is perfect for those looking to save on printing costs while maintaining quality results.