I had been using off brands ink and it was causing my printer to not print properly and the ink would clog up. Now I have sworn to use only HP ink. It may cost more but the expense is worth the quality of print.
Even though the black cartridge is double the capacity of the color cartridges I always run out of black ink before using all the color cartridges. This package with 2 black cartridges solves that problem.
The Cyan/Magenta/Yellow cartridge wouldn't work in my HP Officejet Pro 8600 Premium printer. The cartridge were the wrong p/n CN051A and not CN051AN. The printer wouldn't accept them.