Extech 407113 Heavy Duty CFM Metal Vane Anemometer features: Withstands temperatures to 175°F (80°C) and airspeed to 7880ft/min; Display Air Flow (CFM) or Air Velocity plus Temperature; Air Flow displayed in 3 modes: - Instantaneous value - Up to 20 point average or - 2/3 flow value; Built-in RS-232 PC Interface, etc.