The Skywatch Xplorer 1 is a robust, water proof anemometer. It is very precise and will instantly measure wind speed with an accuracy of +/- 3%. This is a must have for any sport enthusiast where wind plays an important factor. It is compact and fits easily into your pocket. The Skywatch Xplorer 1 features a replaceable lithium battery, 3 wind measurement modes – instant, maximum and average and 5 measurement units. A helpful feature for saving batter life is that the Xplorer 1 will automatically turn off after 1 minute. With an Xplorer anemometer you can say good bye to wasting time on the beach deciding which sail or kite to rig up. Now you can easily check the wind speed and make your decision.  Features Dimensions : 41 x 93 x 17 mm Weight : 50 gr Precision : +/- 3 % 5 measurement units : km/h, mph, knots, m/s and fps 3 wind measurement modes : instant, maximum and average Replacement Lithium Battery Waterproof Operation Temperature -20°C to 70°C