For my Epson Office BX525WD (purchase in December 2010), who has now printed a year of the first set of color cartridges, the ideal refill. Cyan, magenta, yelloow = welded individually and interchangeably disconnected when the very last message of the printer is: cartridge is empty! So the expensive color ink cartridge is utilized to the last drop.
Yellow is still waiting for his replacement.
Black (Black T1301) is a separate XL cartridge and was in addition ordered, but so far not needed and is still waiting for the exchange, if after the current memories comes the low-level control.
Purchase recommended!