The Celestron TrekGuide Digital information center is perfect for hiking and other outdoor activities. The display is large and easy to read under any conditions. The TrekGuide displays a lot of information clearly Time, calendar, altitude, barometric pressure, weather forecast, compass reading, and more. Dimensions: 4" x 1/16" x 5".Digital compassAltimeter - feet or metersBarometer Weather forecast - using iconsTemperature - F or CCurrent timeCalendar AlarmBubble level (for the compass) BacklightWater resistantUses 2 CR2032 batteriesIncludes lanyard.