Leaton Portable LCD Digital Anemometer Wind Speed Meter Air Velocity Air Temperature Meter with Vane Sensor (inclued Battery) (LD8901) Fast, easy, and accurate measuring Range: 0 - 45 m/s, 0 - 140 km/h, 0 - 8800 ft/min, 0 - 100 mph, 0 - 88 Knots. Operating Humidity: 40% RH - 85% RH Storage Temperature: Between -20C and +60C, between -4F and 140F Five Units of Air Velocity: m/s, Km/h, ft/min, Knots, mph.