Garmin eTrex Waterproof Hiking GPS Global positioning system (GPS) receiver continuously tracks and uses up to 12 satellites Calculates current and average speed, time of sunrise and sunset, trip distance, and more Automatic track log--10 saved tracks let you retrace your path in both directions Tough waterproof case; runs for 18 hours on 2 AA batteries Compatible with optional Garmin MapSource software for downloading trip and waypoint data (not map compatible)