This is a compatible replacement for the HP Q7551A MICR (51A) black laser toner cartridge. Specifically designed for printing professional checks, this toner contains a special iron that enables detection and processing through bank scanning systems. With a yield of up to 6,500 pages, it provides an economical alternative to expensive OEM cartridges. The use of this compatible toner does not void your printer's warranty and is backed by a 100% Satisfaction Guarantee.