Anemometer Portable Wind Speed Meter Gauge Air Volume Measuring Meter with Backlight for Weather Data Collection and Outdoors Sports Windsurfing Kite Flying Sailing Proster Anemometer: m/s: 0.40~30.0 (2.0% reading+50); ft/m: 80~5900 (2.0% reading+50); km/h : 1.4~108.0 (2.0% reading+50); mile/h: 0.9~67.0 (2.0% reading+50); Knots: 0.8~58.0 (2.0% reading+50) CFM: 0 to 99990 0 to 9.999ft2; CMM: 0 to 99990 0 to 9.999ft2; CMS: 0 to 9999 0 - 9.999 m2 Multi-function: Reading hold, maximum, minimum, etc for Hand-held or Fixed Measurement. Portable and Professional: Large LCD display backlight measuring instrument, easy to read data in dark. Power Supply: 9V6F22 Battery (Included), low battery indicator with auto power off functions.