The Crowtail-NFC module (Near Field Communications) uses a highly integrated transceiver module PN532 which handles contactless communication at 13.56MHz. It is designed to use IIC (default) communication protocols. In addition, you can also use UART communication protocols via change the connection between the welded plates.
You can read and write a 13.56MHz tag with this module or implement point to point data exchange with two NFC Shields.
Uses as a PFID reader with Mifare one tags and cards(13.56 MHz).
It can support UART, IIC(default) interfaces.
It has 13.56MHz independent PCB antenna.
Max operating distance for detecting NFC tags is 28mm depending on current antenna size.