Search for lasers or laser and you will find a variety of sights you can see. I also specialize in GPS's. GPS stands for global positioning system. The gps uses 24 orbiting gps satelites. The unit must have at least 3 satelites to get your location.
Most units have things called waypoints.
Waypoints are what you use to mark a location to navigate your way back to it. All garmin units have waypoints. More complex units, such as Emap, has your location put on a map. It shows which road you're on and much more. I would like to see how you have found my sight and if you enjoyed it.