Before ordering, I found it very advantageous Pack price perspective but I was afraid that it is not compatible with my printer Canon Pixma MP550; but everything works perfectly, the printer recognizes the cartridges and the ink level; No worries, I am very satisfied and my next order will be the same. Just be careful when opening the cartridges, a drop of ink can escape. It is best to do this over a paper towel and wipe the edge directly from the cartridge; Once wiped, there is no problem.