Displays wet bulb, dew point, humidity and temperature. No twirling or charts necessary. Large digital display. Dew point measurement. Wet and dry bulb temperature. Min/max memory with reset key. F or C readings. Data hold. Auto power off. Low battery indication. Microprocessor based design. Temp. range: -4 to 122 F (-20 to 50 C). Humidity range: 0 to 100 percent RH. Dew point: -22 to 122 F (-30 to 50 C). Temp. accuracy: plus/minus 1.8 F (plus/minus 1 C). Humidity accuracy: plus/minus 5 percent of reading. Response time: 60 seconds (approx.). Dimensions: 6.7 x 1.85 x 0.5 in. Power source: 2 AAA battery. Includes protective cap with pocket clip and batteries.