Wireless Anemometer with wind speed and direction sensor &ndash; Wind Gauge for Netatmo Weather Station Measure wind with a Revolutionary Ultrasonic technology Ultrasound = no inertia. Unlike the Mechanical wind gauges Ultrasound = the best accuracy for wind direction Receive alerts on your smartphone and track historical graphs on the app (smartphone, tablet or pc) The NETATMO wind gauge only works with the NETATMO weather station, sold separately