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.Supports EM4100 CardSize: 95 x 61 mmPower: USBFrom PC interface: USB, 106bit/ s, no driver is needed.Read range: 8cmfrequency: 125kHzoperating temperature: -30C to +60Coperating humidity: 5% -95% (relative humidity, non-condensing)Audio/ Visual indicator: LED and output buzzerweight: 100goutput format the card number: 4H8D, 6H8D etc (selectable within Springer-resistance)Material: Plasticdelivery: 2X USB Proximity Reader ID Card2X USB CableOnly the above package content, other products are not included.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.