A simple and easy to use odometer. GPS Odometer only does one thing, and does it well: measure distance traveled. Includes run in background capability. Ideal for almost anything that requires measuring outdoor distance traveled such as walking, running, driving, boating, hiking, horseback riding. Note that GPS does not work well under a roof. For best results, use outdoors. Features:- accurate to within 1 percent when compared to most car odometers under normal driving conditions.- includes a timer- includes a lock to help prevent accidental reset of your trip. After unlocked, it locks back in a few seconds, or you can lock it yourself.- includes displacement readout (straight line distance from your starting point)- average or actual speed readout- includes meters, kilometers, yards, feet, miles and nautical miles- approximates distance traveled in some GPS dead spots such as driving through a tunnel by adding the as-a-bird flies distance to your trip.- accounts for the curvature of the EarthDistance units include: kilometresmilesnautical milesmetresfeetspeed units include:kilometres per hourmiles per hournautical miles per hourmetres per secondfeet per second Please note that continued use of GPS running in the background can dramatically decrease battery life. Make sure that you pause the trip when you are finished. When the trip is paused, the timer stops.