1、8 in 1 Functions: Contains digital altimeter, digital barometer, digital compass, weather forecast, time, calendar, thermometer and backlight. 2、Altimeter and Compass: Altimeter range: -2296 to 29500 feet, can record 256 historical altitudes; compass shows bearing in degrees and cardinal points. 3、Thermometer and Clock: Thermometer is freely switchable in Celsius, Fahrenheit format; Clock in 12‑hour or 24‑hour format. Backlight is provided for you whenever you press any button. 4、High Accuracy: The digital compass is based on electronic orientation sensor and air pressure sensor technology for precise measurement. 5、Outdoor Use: The digital altimeter is designed for outdoor use, and the detachable lanyard makes the digital compass the perfect handheld device for all kinds of outdoor activities.