Passive RFID technology uses very small tags without batteries, but function similarly to active RFID. Passive RFID tags receive their energy from their readers by absorbing the reader's energy and "reflecting" their identification back to the reader. Passive RFID is suitable for choke point tracking of people using disposable wristbands or for tracking inventory, controlled items (pharmaceuticals), or high value items (heart stents). Key attributes of the technology: