This is an easy to use, functional & lightweight GPS navigation device that due to its wrist mounting makes it perfect for when you need your hands free for more important duties. Foretrex 401 automatically keeps track of your path & displays it as a dotted trail on the screen. This is called a Tracklog & is basically an electronic bread crumb trail of exactly where you have been. To follow the tracklog back to your start point, simply turn on Foretrexs Trac Back feature, & you can retrace your path back to where you started. The electronic compass & barometric altimeter will keep track of your bearing & altitude & the compass will show a bearing even when you are stationary. Specific locations can be stored in the internal memory as waypoints giving you the ability to instantly navigate to your favourite places & important references. You can then link up the stored Waypoints to create routes for the Foretrex to guide you. The Foretrex runs off replaceable & easily sourced AAA batteries, providing up to 17 hours of use. To further increase the capability of this superb device you can connect the Foretrex 401 to a wireless accessory, such as a heart rate monitor, cadence sensor, or clip it on your bike with the accessory bike mount. To keep track of your trip, connect your Foretrex to your PC or Mac with USB (Universal Serial Bus) to store your waypoints, routes & tracks on your computer. You also can share waypoints, routes & tracks wirelessly with certain Foretrex, Oregon & Montana devices, & it also is compatible with Garmin heart-rate monitors & cadence sensors. With a simple connection to your computer & the Internet, you can get detailed analysis of your activities & send tracks to your outdoor device using Garmin Connect. You can even view your activities on a map using Google Earth. In the box: Foretrex 401 Wrist expansion strap USB (Universal Serial Bus) cable Owners manual on disk Quick start manual