Inkfarm's 200xl cartridges come in an 8 pack consisting of 2 sets - an "A" set and a "B" set. In order to use the cartridges, you must first use the A set. Once the A set has been exhausted, you can then use set B. You will need to follow these steps with every order switching between set A and B. If you exchange one set A with another set A, the cartridges will not work. This is the same with set B. For any questions you may have, please use our online email form
, or call us between 9:00 AM and 5:00 PM PST at 1-800-465-3276.