5PCS New ARC Chip for HP 564 Chip for CIS CISS Refillable Cartridge
Most HP cartridges come with embedded chip and it has two functions: 1) Count the number of pages printed and guess how much ink left in the tank.  There is no "Ink gauge" or "Ink sensor" in the cartridge and the printer simply counts how many pages printed on a chip.  For instance, 564XL Black is supposed to print 550 pages and your cartridge printed 225 pages, and then the printer says it is half-empty.  What if you printed 250 pages but didn't use any black ink?  Your printer will still show the black is half-empty (although it is full).  2) Prevent cartridge refill.  HP encrypted the chip data with 128-bit encryption therefore you cannot reset the number of pages to zero.  However, after losing a class action lawsuit, HP allows the cartridge to keep printing with "empty" chips by turning off the ink level monitor on the printer (Setting->Preference->Chip Usage Info->Turn Off).  There are two ways to move away from expensive HP ink: 1) Refill the original HP cartridge.  BCH provides detail instruction on its website. 2) Use a third party refillable cartridge or Continuous Ink Supply System (CIS).  Either way, you will need to find a chip that's going to last forever.There are currently three different kinds of chip solutions:1)      Used original HP chip.  You can take an OEM chip, remove the chip and transfer to your third party cartridge.  Pros: the chip is made by HP.  It was working before.  The chip doesn't deteriorate, so it is as good as new.  Cons: HP re-designed the chip.  New style cartridges will be equipped with hard-to-removable chip (picture).  The "old style" removable chip becomes more and more rare and the price has gone up.  2)      Third-party "Gray" Chips  (THIS LISTING).  :  Sometimes it is called "ARC" chip.  ARC refers to "Auto Reset Chip".  These chips normally come in green color and manufactured in China.