Access Unit
A message sent to/from the MLU (similar to a cell phone minute)

Geo-Fence
An invisible electronic boundary established around the radius of your vehicle.

GPS
Global Positioning System - navigational system using satellite signals to fix the location of a receiver on or above the earth's surface

MLU
Mobile Locating Unit - the actual GPS transceiver that is installed in your vehicle

Monitoring Plans
Monthly service plans of Access Units used to communicate with your Millennium Plus Unit.