The Grey ink is added to the standard Cyan, Magenta, Yellow, and Red inks to achieve superior photo quality.
It offers a high page yield, often estimated at up to 8,000 pages or 3,800 4x6 inch photos per bottle.
It is specifically designed for Canon PIXMA MegaTank Photo Printers that use the 6-color GI-73 ink system, including models like the Canon PIXMA G570, G670, G550, G650, and G620