HP Wide Format Z2100 Continuous Ink System (HP 70 series cartridges) REFILL KIT. This is a BISONTEC refill kit to replenish the ink in our BISONTEC Continuous Ink System. This BISONTEC refill kit is the perfect buy for high volume printers at less than $50 this represents over 90% savings compared to buying new OEM cartridges! Remember the ink in this refill kit is UV resistant and matches the OEM quality in both quality and page yield.