Professional measurement: It can be used to measure wind speed, air volume, temperature, wind direction angle and humidity, and it gives the max/min value, Air volume 2/3 MAX value and average value. Widely used: It is used in factory, school, office, traffic, family and many other different occasions. Real-time measurement: Designed with USB for connection to the computer. Multifunctional: Backlight & data hold function; Low battery indication function; Automatic on/off setting function. Selection unit of measurement:Details in Specification in the following description. Specifications: Wind speed measuring range: Unit Wind Speed Range Resolution Minimum threshold Precision m/s 0.0 ~ 45.0 0.01 0.3 ± 3% ± 0.1 Ft / min 0.0 ~ 8800 0.01/0.1 60 ± 3%±20 Knots 0.0 ~ 88.0 0.01 0.6 ± 3% ± 0.2 Km/h 0.0 ~ 140.01 0.01 1 ± 3% ± 0.4 Mph 0.0 ~ 100 0.01 0.7 ±3%±0.2 Air volume measuring range: CFM:0~999900 ft3/min CMM:0~999900m3/min Unit range resolution area CFM(FT3/MIN) 0~999900 0.001~100 0.001~9999ft2 CMM(M3/MIN) 0~999900 0.001~100 0.001~107.6 28.4 sqm Unit conversion: m/s Ft/min Knots Km/h Mph 1m/s 1 196.87 1.944 3.60 2.24 1ft/min 0.00508 1 0.00987 0.01829 0.01138 1 bun 0.5144444 101.1 27 1 1.8519 1.1523 1 km/h 0.2778 54.69 0.54 1 0.6222 1mph 0.4464 87.89 0.8679 1.6071 1 Air temperature: (1) temperature measurement range Unit Range Resolution Accuracy °C 0 ~ 45 0.1 ± 1 C 32 ~ 113 0.18 ± 1.8 °F (2) Humidity measuring range Temperature 0~5°C(32~122°F) Humidity 40~80%RH Storage Condition: Temperature -40 ~ 60 C (-40 ~ 140 C) Humidity ≤ 80 %RH Power supply: 4 x 1.5 V AAA alkaline batteries (not included) Package contents: cordless drill with knock function and 3 speeds, 1 x 1 ×Anemometer