This magenta along with yellow and cyan cartridges have been working fine despite it being not an original HP cartridge. Can't say the same all the time, I have had some work and not. It may have to do with windows updates that makes it recognize that this is not an OEM product. One important thing about this is, note that this is NOT an XL size. You can only fit one XL cartridge in 8500A and that's in the black cartridge slot. XL is double the thickness, this one is regular size.