Here we offer you a high quality and tiny desktop EM card reader with USB interface. He can read the ID number of 4100 EM 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: -30°C to +60°C operating humidity: 5% -95% (relative humidity, non-condensing) Audio/ Visual indicator: LED and output buzzer weight: 200g output format the card number: 4H8D, 6H8D etc (selectable within Springer-resistance) Material: Plastic delivery: 4 x ID card reader 4 x USB cable Only the above package content, other products are not included. Note: Light shooting 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.