The PN532 is actually a bundle of 4 libraries: PN532, PN532_HSU, PN532_I2C and PN532_SPI. You only need 2, the main PN532.h and either the I2C or SPI depending on how you connect it. The HSU is for high speed communication, which you probably won't need.Important: Before getting it start, you need to install a few libraries like Don's NDEF library, PN532 library(Seeed-Studio's version recommanded), both of them you can find on GitHub or at below links: Arduino Library for NFC Shield based on NXP PN532 chip: https://github.com/jmgjmg/PN532 Arduino library for SPI and I2C access to the PN532 RFID: https://github.com/adafruit/Adafruit-PN532 Driver for PN532 NFC chip: https://github.com/techniq/node-pn532Description: 1. Gilt PCB and Small dimension and easy to embed into your project 2. Support RFID reading and writing SupportP2P communication with peers Support NFC with Android phone 3. Typical Operating Distance have been updated to 5cm~7cm reading distance 4. Work in NFC Mode or RFID reader/writer Mode 5.RFID reader/writer supports: 1) Mifare 1k, 4k, Ultralight, and DesFire cards 2) ISO/IEC 14443-4 cards such as CD97BX, CD light, Desfire, P5CN072 (SMX) 3) InnoVISION Jewel cards such as IRT5001 card 4) FeliCa cards such as RCS_860 and RCS_854 7. Plug and play, Arduino compatible 8. Built in PCB Antenna, with 4cm~6cm communication distance 9. On-board level shifter, Standard 5V TTL for I2C and UART, 3.3V TTL SPI 10. Work as RFID reader/writer 11. Work as 1443-A card or a virtual card 12. Exchange data with other NFC devices such as smartphonePackage Incuded: 1*NXP PN532 NFC RFID Module V3 Kit