Sophia Global Remanufactured Ink Cartridge Replacement for Lexmark 28 (2 Black) Backed by a 100% Guarantee and a Two-Year Warranty ISO 9001 Quality Certified Manufacturing Process Up to 175 pages per black These Lexmark 28 cartridges were professionally remanufactured in an ISO 9001 factory. These cartridges were used once and then sent to our factory where they underwent an extensive process including cleaning, testing the chip, and ink refilling. Before being sealed, the cartridges were tested in a live printer to ensure crisp text and true color reproduction. The cartridges were finally sealed and placed in a static protective bag.