Core's come with a tiny eeprom and are labeled typically "AA 0.4".  3dsolex cores usually are also labeled "AA 0.4" for convenience.  The older 3dsolex cores were labeled "HardCore".   This caused some consternation with the printer firmware and also with cura if cura is reading your printer over the network.  It was pretty minor (just hit "ignore" a few times) up until Ultimaker updated how they allow you to print over the network.  The latest version of cura refuses to let you print
    • Thanks
    1