Precise and reliable measurements of barometric pressure, altitude, wind speed, temperature, wind-chill and time. The Alti-Windwatch is the ideal portable weather station for all outdoor activities such as hang gliding, paragliding, ballooning, ultralight flying, skiing, mountain climbing, trekking, sailing, field studies and many others. Waterproof to 16 ft. Battery life approximately 4 years. 2 year warranty.