The nice thing about this reader is that its packaged in plastic, has an LED and buzzer to indicate when a card is read, and spits out the 4-byte card ID over the USB cable as if it were a keyboard. It cannot read or write the contents of the card, its only good for reading the permanent  4-byte ID burned into each MiFare classic 13.56 Mhz tag.

• USB  or serial RS232 interface
• Read and write functionality
• Built-in antenna for contactless tag access, with card reading distance of up to 50mm
• Supports major contactless smart cards conforming to ISO 14443 Type A and B in the market
• Built-in anti-collision feature  (only 1 card is accessed at any time)
• Selective card polling capability (especially useful when multiple cards are presented)
• Operation LED
• Buzzer