Ultra compact micro-design is small in size and big in features. Unit measures air velocity in five user selectable values: meters per second, feet per second, miles per hour, kilometers per hour, and knots. It also displays: maximum airflow measured, temperature in °F and °C, and wind chill temperature in °F and °C. Measurements are lightning fast with reading updates 2 times per second. Simple one-button operation eliminates the need to refer to directions.