The Kestrel 4500 Weather Meter features a digital compass, wind direction, crosswind, headwind/tailwind, barometric pressure, pressure trend, altitude, relative humidity, heat stress index, dew point, wet bulb temperature, density altitude, wind chill, air/water/snow temperature, current wind speed, average wind speed, maximum wind gust, time and date, exterior temperature and pressure sensor, 4000 data points, graphs and recall trends, data charting, and a flip-top, user-replaceable impeller. Kestrel 4500 Complete Weather & Environmental Meter 0845