Description:The device is based on the technology of electronic bearing sensor and barometric sensor. The digital altimeter is designed for outdoor use, the detachable string makes the digital compass a perfect hand-carry device for various outdoor activates it will give you backlight when you press any button in any time. Features:1. Made of high quality ABS plastic material, which is durable, corrosion resistant and environmental friendly.2. The device is based on the technology of electronic bearing sensor and barometric sensor.3. With a rope that very convenient to carry.4. For outdoor sports enthusiasts with a wide range of essential and more precise information. 5. Ideal for outdoor sports enthusiasts made the simple type of equipment. Specifications:Material: ABSColor: BlackSize: approx. 9 x 5 x 2cm / 3.54" x 1.96" x 0.78"Strap Material: Cotton FabricBattery: 2 x AAA batteries (not included)8 in 1 Function: Altimeter(Range): -700 meters - 9000 meters / -2300-2950ft (resolution ratio-1m/3ft)Barometer(Range): 350mbar-1100mbar (resolution ratio-0.1mbar)Digital Compass: show bearing in degrees and cardinal pointThermometer(Range): -10 Degree to +60 Degree, (Format ):°F/°CWeather Forecast: Start the machine, it can forecast the weather in the next 12-24 hours, the effective range of 30-50kmLED Backlight: In any state, press any key to open the backlight, when open backlight, press any key to extend the time of 5 secondsClock Format: 12Hr/24Hr (AM/PM)Battery: 2 x AAA batteries (Not Included)Package Included:1 x digital altimeter1 x rope1 x manualNote:1. Avoid use in rain, damp, too high or too low temperature (working temperature: 0℃-50℃, storage temperature: 20℃-70℃）2. Avoid contact with corrosive material such as perfume, alcohol, cleaning agents and so on.3. Avoid use in a area that maybe effect the magnetic compass normal use:Near the concrete/steel structuresClose to power stationsClose to home appliances (such as computer, TV, VCD, fax machines, speakers,etc)Close to the bridge which made from lots of steel or metalClose to the running vehicles (cars, trains, airplane)Near or on the surface of the metal plate.