Proximity Entry Cards
Proximity entry cards (or Prox Cards) is a generic name for contactless integrated circuit devices used for security access or payment systems. It can refer to the older 125 kHz devices or the newer 13.56 MHz contactless RFID cards, most commonly known as contactless smartcards. Modern proximity entry cards are covered by the ISO/IEC 14443 (Proximity Card) standard. There is also a related ISO/IEC 15693 (Vicinity Card) standard. Proximity entry cards are powered by resonant energy transfer and have a range of 0-3 inches in most instances.