Celestron WindGuide Plus Anemometer puts all the comprehensive features of a weather station in your pocket. These feature-packed weather instruments are highly accurate at measuring current and maximum wind speeds over time, up to 67 miles per hour. When the temperature drops below freezing, the anemometer will even calculate the wind chill. But wind speeds are only part of what these Celestron weather instruments are capable of. The Celestron Wind Guide Plus Portable Anemometer Weather Instrument will measure altitude up to 9000 meters, barometric pressure, and even the relative humidity percentage, giving you all the information you need to deduce current and possible future conditions. A bright blue backlight makes the anemometer easy to read in low light, and its weather resistant construction makes ideal for extreme sports like kite surfing, snow boarding, and water skiing. The WindGuide Plus notifies you when its CR2032 battery is running low, allowing you to conserve power for when you really need it. Celestron has included a carrying pouch and a lanyard with the WindGuide Plus to keep the anemometer safe and easily accessible. For an anemometer that measures more than just wind speed, slip the Celestron WindGuide Plus Pocket Weather Anemometer in your pocket.