Hi Forum,
Can you help me identify (see pic attached) please?
Size of a £2 coin, sticky on one side ( the silver circuitry side) black plastic on the other , thickness of paper , number 5 and ta written on???
What is it , what are they used for ?
Regards

g

 

Looks like an RFID tag. A reader powers and activates it with a kHz frequency, and the tag sends out its serial number on a different frequency.