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 Card Size: 95 x 61 mm Power: USB From PC interface: USB, 106bit/ s, no driver is needed. Read range: 8cm frequency: 125kHz operating temperature: -30C to +60C operating humidity: 5% -95% (relative humidity, non-condensing) Audio/ Visual indicator: LED and output buzzer weight: 100g output format the card number: 4H8D, 6H8D etc (selectable within Springer-resistance) Material: Plastic delivery: 2X USB Proximity Reader ID Card 2X USB Cable Only 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.