The Extech 45158 is a waterproof pocket sized Thermo-Anemometer for Air Velocity, Temperature and Wind-chill measurements. Simultaneously display Air Velocity and Temperature or Wind-chill on the LCD screen. Selectable averaging function of 5, 10, or 13 second intervals. Fold up protective housing extends to 9 in. (229mm) for a better reach. Tripod mountable. Features Data Hold with Auto power off functions.