The mini NFC shield uses the PN532 chip-set (the most popular NFC chip on the market) and is what is embedded in pretty much every phone or device that does NFC. This chipset is very powerful, and can pretty much do it all, such as read and write to tags and cards, communicate with phones (say for payment processing), and act like a NFC tag. While the controller has many capabilities, our library currently only supports reading/writing tags, and does not support phone-to-shield communication, tag emulation (which requires an external secure element only available from for NXP) or other more advanced features at this for time. NFC (Near Field Communications) is a way for two devices very close to each other to communicate. Sort of like a very short range Bluetooth-compatible that doesn for t require authentication. It is an extension of RFID, so anything you can do with RFID you can do with NFC.Because it can read and write tags, you can for always just use this for RFID-tag projects. We carry a few different tags that work great with this chip. It can also work with any other NFC/RFID Type 1 thru 4 tag (and of course all the other for NXP for MiFare type tags) R3 or later. For using the I2C interface with Mega R2 or earlier, two wires must be soldered as the I2C pins are in a different location on earlier Megas. Size: See the picture No retail package Quantity: 1Pc Note: Due to the difference between different monitors, the picture may not reflect the actual colorof the item. '