The Epson 664 EcoTank ink cartridge, in magenta, contains 70ml of ink and yields approximately 7500 pages. It is part of the Epson EcoTank system, where ink is replenished via dedicated 70ml bottles directly into the printer's ink tanks, instead of disposable cartridges, significantly reducing the cost per printed page over time. It is compatible with Epson EcoTank printers L555, L355, ET-2500, ET-2550, ET-2600, ET-2650, ET-3600, ET-4500 and ET-4550. It is a preferred option for those who regularly print color documents and want to keep the cost per page as low as possible.