We are Guangzhou D-think intelligent technology Co., Ltd based in Guangzhou , China. We are member of Tradekey.com since April, 2011. Our business is related to Security & Protection industry and we specifically deal in RFID reader/module;RFID tags;card;key RFID tags. Please find our product details below:EM4100&Compatibility RFID LF ReaderSpecifics:Support chips:EM4100 or compatible with the TK4100, GK4100Interface:USB2.0Indicator:Red, built-buzzerRead distance:5-10CM(depends on the antenna structure and the appilication envirThank you for taking the time to go through our business profile. If there are any question, inquiry or comments, please feel free to contact us.