The next generation of weather monitoring! Now, you can measure every major environmental condition easily and accurately, right in the palm of your hand. The chart mode allows users to recall and graph up to 250 measurements, along with date and time of storage. Barometric pressure, altitude, density altitude, temperature, humidity, wind speed, wind chill, dew point, wet bulb, and heat index - all in one pocket-size instrument. Waterproof and buoyant. Comes with a slip-on case and lanyard. Uses 2 AA batteries(included)