RFID card reader is easy to operate and has fast card reading speed. If it is a standard HID device, there is no need to install the driver. The card number can be read in any edit box (for example: Notepad, WORD and other text editing software). This function is suitable for expanding the functions of existing software without making any modifications to the original software Communication mode: standard HID communication; Interface: full-speed USB device interface, compatible with USB V2.0 Power supply mode: USB universal serial bus interface power supply; Working frequency: 125 KHz; Maximum sensing distance: 3-8CM; Supported card types: EM series, 4001 series and compatible radio frequency ID cards; Power consumption: less than 0.5 W; Use environment: temperature 0--50℃, humidity: 50-95RH, air pressure: 88-106Kpa. Product appearance may vary slightly between different batches, but this does not affect use. Colour:black Material:plastic Package Contents: 4 x USB RFID Reader Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.