eTrack makes use of GSM, GPS and Bluetooth technology, which enables it to be tracked by a smartphone, while eTag also utilises Bluetooth. Passengers with a Flying Blue account can link the eTag and eTrack devices to their account, so when they check-in online, the permanent bag tag will be automatically updated within just five seconds.The tag communicates with the outside world via the eTrack device, and directly with smartphones using Bluetooth, but the two products can also be used independently.“Bluetooth technology is used worldwide, so it makes sense for us to use it,” van Lijf stated. “With things like NFC (Near Field Communication), you would need to use more antennas, which would mean the tag would have to be bigger. We could add NFC later, but Bluetooth works fine.”The eTag includes two e-ink displays and attaches to the outside of the suitcase, while the eTrack tracking device is placed inside the suitcase.