I’m confused on what you are reporting.
You say your OEM cart is a T603700 and that is the LK model number for an Epson 7800 printer.
What we shipped you was a T6047 and that is the LK model number for an Epson 7880 printer.
Are you sure you have an Epson 7880 printer?
From what you are reporting you own a 7800 printer.
You did order for the Epson 7880.
Can you double check on your end?[/QUOTE]
Yes, it says EpsonStylus Pro 7880 on the printer. The OEM carts in it are numbered T603x, I’ve replaced several in the past with Epson cartridges. They measure 7.25 inches long. I just looked at another Epson cart, T6031, the label says it’s for7800/9800/7880/9880, so these printers must all accept the same cartridge.