When you select Pack Size, make sure you also look at the photo that is displayed This is what you need to see if you have selected the correct one.
Item specifics:
Original Epson 603XL, High Capacity Ink Cartridges, T03A1, T03A2, T03A3, T03A4, T03A5, T03A6,
Model: 603XL
Brand: Epson
Capacity: High Capacity
Ink Volume: BK=8.4ml, C/M/Y= 4.0ml Each Colour
Page Yield: Approx. 500 black / 350 colour pages @ 5% average coverage
Technology: Ink Jet Printer Cartridges
Product Type: Genuine/Original
Condition: New (Blister Packaging, without box, Foil Vacuum Sealed)
Warranty 1 Year

Please select correct Ink Cartridge and Qty Available in Variations:
1 X EPSON 603XL Black - T03A1, C13T03A14010
2 X EPSON 603XL Black - T03A1, C13T03A14010
1 X EPSON 603XL  Cyan - T03A2, C13T03A24010
2 X EPSON 603XL  Cyan - T03A2, C13T03A24010
1 X EPSON 603XL Magenta - T03A3, C13T03A34010
2 X EPSON 603XL Magenta - T03A3, C13T03A34010
1 X EPSON 603XL Yellow - T03A4, C13T03A44010
2 X EPSON 603XL Yellow - T03A4, C13T03A44010
1 X EPSON 603XL CMY - T03A5, C13T03A54010 = 3-Colours
1 X EPSON 603XL MAltipack - T03A6, C13T03A64010 = 4-Colours
1 X MUltipack T03A6 + 1X Extra Black 603XL, T03A1, C13T03A14010, C13T03A64010 = 5-Colours
1X Epson 603XL Black T03A1 + 1X EPSON 603, T03U2/T03U3/T03U4, EPSON 603, T03A9, C13T03U94010 = 4-Colour
Item description:

USE With

Expression
These Epson Expression Printers works The 603XL Ink Cartridge:
XP-2100 ink cartridges
XP-2105 ink cartridges
XP-2150 ink cartridges
XP-2155 ink cartridges
XP-3100 ink cartridges
XP-3150 ink cartridges
XP-3155 ink cartridges
XP-3105 ink cartridges
XP-4100 ink cartridges
XP-4105 ink cartridges
XP-4150 ink cartridges
XP-4155 ink cartridges
WorkForce
These Epson Work Force Printers works The 603XL Ink Cartridge:
WF-2810DWF ink cartridges
WF-2820DWF ink cartridges
WF-2830DWF ink cartridges
WF-2835DWF ink cartridges
WF-2840DWF ink cartridges
WF-2845DWF ink cartridges
WF-2850DWF ink cartridges