The Global Positioning System (GPS) is a space-based global navigation satellite system that provides reliable location and time information in all weather and at all times and anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.

The PND is used only as a navigation aid. It is not for precise measurement of direction, distance, location or topography. The user must follow all traffic signs and local regulation or topography. The user must follow traffic signs and local regulation along the roads.

GPS satellite signals cannot pass through solid material, but except glass. When you are inside a tunnel or building, GPS positioning is not available.

A minimum 4 GPS satellite signals are needed to determine current location. Signal reception can be affected by situations such as bad weather or wireless devices or dense overhead obstacles. Example, tall building

When you get out the car, do not leave your PND on the dashboard or subject to direct sunlight. The overheating of the battery may cause malfunction and dangerous condition.