4inkjets.com's compatible Lexmark 521 black laser toner cartridge is guaranteed to perform with your Lexmark laser printer. The compatible replacement 521 laser toner cartridges and supplies (also known as generic) are specially engineered to meet the highest standards of quality, reliability and exceptional yields that meet or exceed OEM (Original Equipment Manufacturer) standards for the 52D1000 Lexmark laser cartridge and offer high-quality printing results. Manufactured brand new, containing 100% new components, they are an economical alternative to expensive OEM 52D1000 Lexmark laser toner cartridges and supplies, and offer big savings over brand-name 52D1000 laser toner cartridges. The use of compatible replacement laser toner cartridges and supplies does not void your printer's warranty. We offer a 100% Quality Satisfaction Guarantee on our compatible 52D1000 laser toner cartridges and supplies.