EXTECH AN320-NISTL Thermo Anemometer, 40 to 5900 fpm. More details: Anemometer, Rotating Vane and Thermistor Sensing Method, Data Logging No, Humidity Sensing Yes, Velocity (FPM) 40 to 5900, Velocity (MPS) 0.2 to 30, Air Velocity Accuracy +/-1.5 Percent, Air Volume 0 to 99, 999 cfm, Temp. Range -4 Degrees to 140 Degrees F, Relative Humidity Range 0.1 to 99.9 Percent, Probe Size 4 In. dia., Data Hold Yes, Auto Power Off Yes, Calibration Certificate NIST, Includes Instructions, Batteries, NIST Certificate of Calibration and Hard Case