My wife just arrived back from a trip to USA. On her luggage, she found this label:
She gave me three of them. Turning them over showed that they where RFID labels:
It's had to see above, but in the top, middle of the central circle there is a RFID chip. Here is a close up of the tiny RFID Chip:
It's around 0.58 of a mm in size. The marks above are 1mm from a plastic ruler.