Sophia Global Compatible Ink Cartridge Replacement for Dell 21 (2 Color, 2 Black) Backed by a 100% Guarantee and a Two-Year Warranty ISO 9001 Quality Certified Manufacturing Process Page Yield: Up to 180 pages for each black and 170 pages for each color These Dell 21 compatible cartridges were professionally manufactured in an ISO 9001 factory. They have never been used and are designed to provide equivalent print life to the original brand name cartridges. The ink is formulated to provide excellent color matching for true-to-life photos and crisp text. The cartridges are engineered to fit exactly into your printer.