These RF4 PCB HF RFID tags are using copper etching technology plus FPC or PCB base material. They are with stable performance; The key feature is that they could make very small nfc tags into real; When you have NFC applications/RFID applications that you need very small nfc tags; please contact us for further discussion. These RFID tags are much more robust than normal Aluminum antenna tags, and can withstand a certain higher temperature. Thus it could be flexilable assembly into special plastic or fabric toys, silicone bands or parts, audio earphone, bluetooth equipment, and all other types of promotional gifts which they would like to join in NFC into. Please see below products with details.