Handheld anemometer c/w 3 cups mounted rotor, automatic backlighting - waterproof and insubmersible, battery operatedFeatures -Wind speed :Scale : 1 to 40 m/s.Units : digital knots, m/s, km/h, mph.Graphic Beaufort force.Maximum wind speed.Average speed on 5, 10, 20 or 40 selected seconds.Accuracy : 4%.Resolution : 0.1 (up to 9.9), 1 (over 10).Air temperature and Windchill :Scale : -20 to +60 °C.Accuracy : 1 °C (2 °F).Units : °C or °F. Resolution : 1 °C (2 °F).