This sale is for 8 chips in total...

1 x Black A Chip, 1 x Black B Chip, 1 x Cyan A Chip, 1 x Cyan B Chip, 1 x Yellow A Chip, 1 x Yellow B Chip, 1 x Magenta A Chip, 1 x Magenta B Chip.

The inkjet cartridges used in Primera LX-900 label printers are equipped with a chip. When the original chip is empty it can not be used again for making a refilled LX-900 cartridge printing again.
On a refilled cartridge the original chip has to be replaced with a new alternative chip. Only with the new, alternative chip the refilled inkjet cartridge will be recognized by the Primera LX-900 printer and can be used for printing labels.

The alternative chips are one time chips too. That means after each refill of a cartridge it is necessary to install a new alternative chip. On the chip´s board there are several important details.

Each alternative chip for Primers LX-900 has a three digit number code for the color. 425 = Black, 422 = Cyan, 423 = Magenta, 424 = Yellow - 

Please make sure to use the right color coded chip according to the color of the refilled LX-900 cartridge. Below that three digit colour code each chip is either marked with the letter "A" or the letter "B". When You have used an A-chip and this one is empty, make sure to use a chip marked with "B" after the "A" chip. 

This ensures that Your refilled cartridge for Primera LX-900 is recognized by the printer and You receive proper ink level information.