Phoenix Comicon announced today that after the initial run at Phoenix Fan Fest, the RFID wristbands would be debuting at Phoenix Comicon next May (actually they announced this a while back but just now made it official).
The wristbands are a lightweight band that secures to your wrist (which means no taking it off without cutting it off IF they are the same as they were during Fan Fest). You will tap in upon entering areas such as the exhibitor hall and theoretically other areas such as panel hallways, gaming areas, and so on. You can also expect to tap out when exiting those areas.
The wristbands will be mailed out if you make your purchase before the cut off mailing date of April 13th at 5PM. For more updates on Phoenix Comicon as they happen, make sure to follow Legion of Sand on Twitter!