The Humminbird's ION Series of displays are Integrated MFDs which provide the flexibility to build multi station, fully networked navigation systems having options for Automated Identification Systems (AIS), Digital Radars, various types of Sonar modules, IP based cameras and NMEA0183 or NMEA2000 connectivity. While Humminbird's ONIX Series has the same integrated functionality, it is not considered a MFD because this product comes standard with GPS and Sonar in each purchase.  

In contrast, an MFD can offer many types of integrated internal functions but usually is stand-alone display without advanced networking capabilities.