This compact air velocity meter anemometer measures in fpm, m/s, kph, mph and knots. The r1900 keeps track of maximum and average readings and features a data hold function and low friction rotating vane for improved accuracy. features: measures fpm, m/s, kph, mph, knots and temperature designed for one-handed operation backlit dual lcd display beaufort scale max, average and data hold functions low battery indicator and auto shut off