Premium Pigment ink for Epson WorkForce Pro WF-C5390 WF-C5890 WF-C5310 WF-C5810 Printer refillable ink cartridge. 

Options: 

1) 4X500ML

2) 4X1000ML

No refilling instruction is included. 

If you need refillable ink cartridges, please click the link here: HERE