【Accurate Wind Meter】Wind Speed Meter for measuring wind speed range 0.67~67.1 mph(+/- 2% of readings), Wind temperature -10~60℃,14℉-113℉(+/-2℃,35.6℉); Resolution 0.1m/s; 0.2℃. 2 temp sensors and 8 vanes makes this air velocity meter is sensitive to measure very low air flow in HVAC installation, duct vent. A good helper in CFM calculation. Air Flow in CFM (Q)=Wind speed(V) x Duct Cross Sectional Area(A)