HID provides a variety of Prox hardware tailored to different business and security needs: 

While HID Proximity systems are robust and deeply integrated into older security networks, the 125 kHz frequency used by basic prox technology does not have advanced encryption or robust challenge-and-response checks. Because of this, cards can be easily cloned or duplicated with inexpensive readers. To mitigate this, HID Global now offers upgraded, modernized smart card technologies (such as iCLASS or Seos) that feature much higher security and support for mobile access credentials.