Here we offer you a high quality and tiny desktop card reader with USB interface. He can read the ID number of 4100 card or other compatible cards. Once the card is noticed, the ID number of the card will be sent directly via USB to the PC. new and high quality High sensitivity and fast response USB interface, no driver is required He reads the number of the 4100 ID Card or compatible card Support for Card 4100 Dimensions: 95 x 61mm ower supply: USB PC Interface: USB, 106bit / s, no additional driver is needed Distance of operation: up to 8 cm Frequency: 125kHz Material:Plastic Packet content: 1X USB Proximity Reader ID Card 1X USB Cable Note: Light 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.