4inkjets.com's compatible replacement for the HP Q7551X (HP 51X) high yield black laser toner cartridge is guaranteed to perform with your HP laser printer. It replaces the original HP Q7551X laser toner cartridge. Our compatible replacement Q7551X laser toner cartridge is not a remanufactured cartridge, but rather, a brand new toner specially engineered to meet the highest standards of quality and reliability. Although our compatible replacement for the HP Q7551X toner is not manufactured by HP, the page yield meets or exceeds OEM (Original Equipment Manufacturer) page yield and offers comparable printing results. The use of LD compatible replacement laser toner cartridges and supplies does not void your printer's warranty. We offer a 100% Quality Satisfaction Guarantee on our LD compatible Q7551X laser toner cartridges and supplies.