This is the Passive GPS unit that we offer. Offenders who carry this device also have the above ankle bracelet transmitter affixed to their ankle with the same tamper resistant strap. This device utilizes what is called passive GPS tracking where the unit collects GPS points which are uploaded during the charging session each evening. Reporting is then transmitted and can be viewed by the monitor at anytime via a user friendly website. This technology can be offered a cheaper price compared to the active GPS unit, while offering most of the same advantages. More information can always be received by contacting at 866-747-8278.