ERAY Digital Anemometer Wind Speed Gauge Handheld Air Velocity Flow Volume Meter with Backlight LCD Display, Suitcase and Battery Included M/S [Range: 0.40~30.00 m/s; Resolution: 0.01 m/s; Accuracy: (3% + 0.20 m/s)] -- Km/H [Range: 1.4~108.0 km/h; Resolution: 0.1 km/h; Accuracy: (3% + 0.8 km/h)] -- Ft/Min [Range: 80~5900 ft/min; Resolution: 1 ft/min; Accuracy: (3% + 40 ft/min)] -- MPH [Range: 0.9~67.0 mph; Resolution: 0.1 mph; Accuracy: (3% + 0.4 MPH)] -- Knots [Range: 0.8~58.0 knots; Resolution: 0.1 knots; Accuracy: (3% + 0.4 knots)] CMM (cubic meters/min): [Range: 0~9999 m3/min; Resolution: 1; Area: 0~9.999 m2] CFM (cubic ft/min): [Range: 0~9999 ft3/min; Resolution: 1; Area: 0~9.999 ft2] Range: 14~140 F (-10~60 C ); Resolution: 0.1F/C; Accuracy: 4.0F (2.0C)] Display: Dual function 0.5inch (13 mm) 4-digit LCD Sampling Rate: 1 reading per second approx Sensors: Air velocity/ flow sensor: Conventional angled vane arms with low-friction ball bearing; Temperature sensor: NTC-type precision thermistor Automatic Power Off: Auto shut off after 15 minutes to preserve battery life Operating Temperature: 32~122 F (0~50 C ) Storage Temperature: 14~140 F (-10~60 C ) Operating Humidity: &lt; 80% RH Storage Humidity: &lt; 80% RH Operating Altitude: 2000 meters (7000 ft) maximum Dimensions: 202*85*48 mm (Only host computer) Weight: 240 g (Only host computer) Measures Air Velocity, Air Flow and Temperature. With a bulb to light up the LCD screen, it is easy to read the measurements in the darkness. With a standalone fan sensor, just connect it to the host. Please keep the angle of fan and direction of wind within 20 degrees. Air Temperature Range: 14~140 F (-10~60 C ); Accuracy: 4.0F (2.0C)] Default is C, if you want to change it to F, just press the button in the battery case. 1 x Anemometer 1 x Suitcase 1 x 9V Battery 1 x User Manual