RDM6300 125KHz Card Mini-Module is designed for reading code from 125KHz/ 134.2KHz card compatible read-only tags and read/write card . It can be applied in office/home security, personal identification, access control, anti-forgery, interactive toy and production control systems etc. RDM6300 Series non contact RFID module, use the advanced RF receiving circuit and embedded MCU design, combing with high efficient decoding algorithm, to finish the data receive of EM4100 and all the compatible cards. This is a very popular RFID card read module for arduino users, it can read 125K EM4100 series RFID card. This module is easy to use, serial port connect to arduino MCU after power up, when RFID card enter into card reading range, this module will send the card number to arduino by UART You can further connect relay arduino shield to your arduino in order to enable the simple door keeper controlling system.