Dissecting Disney's MagicBand
Wearing the MagicBand allows you to charge meals and other purchases, gain access to attractions, pretty much anything you can think of using an RFID badge for. Here's a quick rundown of the system.
One person decided to take the MagicBand down to the bare metal and see exactly what was going on inside. Being already aware of RFID technology, they weren't too surprised to find an RFID chip and antenna. However, there was also another complete circuit with a battery and larger antenna.
At this point, one might be tempted to stop, curiosity abated. This article does not stop though. The person going by the name "AtDisneyAgain" searched out and found the FCC documentation for the short range RFID system as well as the long range system. You can find all the detailed pictures of the teardown as well as all the documentation of the MagicBand as well as the receiver domes that communicate with it on their website.