The T0543 is the magenta cartridge from the \"Frog\" range of eight Epson cartridges compatible with many printers including the Epson Stylus Photo R1800. This particular cartridge is a recycled Epson original C13T05434010 ink generally known as a remanufactured cartridge. The Epson original cartridge is refilled with a high quality dye based magenta ink and then has the T0543 chip reset to give a full ink reading once installed. As a result the quality and quantity of the prints produced with a remanufactured C13T05434010 should be on a par with a brand new ink cartridge. If however you are not completely satisfied this cartridges comes with our 100% satisfaction guarantee.