This is A professional digital anemometer with stable performance, safety and reliability. It is widely used in wind energy, meteorology, industry, agriculture, hydrology and water conservancy, environmental protection, highways, airports and ports, etc. Data hold;Backlight on or off;MAX/MIN/AVG function;Temperature unit selection;Wind speed unit selection;Auto shutdown function. Specification: Material: ABS Size: 137*56*26mm Display: LCD display, maximum display 9999 Wind speed measurement: Range: 0.70 - 30.00 m/s Sampling time: about 0.5 seconds / time Sensor: impeller + bearing Data Hold: Lock display readings Operating environment: 0-40°C, maximum relative humidity of 80%, altitude <2000m Storage environment: -10-50°C, max 70% relative humidity (battery removed) Automatic shutdown: 10 minutes Power supply: 3 x 1.5VAAA(LR03) batteries (battery not included) Wind speed accuracy: < 1.00m/s: ±0.7 m/s; 1.00~30.00 m/s: ±(2.0%+ 0.5m/s) Temperature range: -20.0°C - 60.0°C (-4.0°F~140.0°F) Temperature Accuracy: 0.0 °C ~ 45.0°C: ±1.0°C; Others: ±1.5°C Humidity range: 0.0% ~99.9%RH Humidity accuracy: 20%~ 80% RH: ±5.0%RH; others: ±6.0%RH Considerations: 1.Do not touch the fan blade with force. 2.Do not store or operate the instrument in areas with high temperature or humidity. 3.In use, do not let the strong light directly shine on the fan, in order to avoid measurement errors. 4.Avoid violent vibration. 5.Remove the battery before storing the instrument for a long time. Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! Please allow 1-2cm measuring deviation due to manual measurement.