The FloRite® 500 and 600 are rotating-vane anemometers for air velocity and volume flow rate measurements. Both instruments have been designed with ease of set up and operation in mind. The user can choose measurements to be displayed on its LCD in either Metric or Imperial units by means of a slide switch located inside the battery compartment. Both instruments are designed for supply and return airflow applications in heating, ventilating and air conditioning systems making air measurement quick, reliable and accurate. The FloRite® 500 (F4397-1) measures air velocity by pressing and holding down the pushbutton located on the side of the handle. The average air velocity is automatically calculated and the digital display updated every 3 seconds over the time period that the pushbutton is held down. The FloRite® 600 (F4397-2) measures air velocity or volume flow rate averaged over a 3 second period by momentarily depressing the pushbutton located on the side of the handle. When the pushbutton is pressed and held down, however, the instrument automatically calculates and displays the average air velocity or volume flow rate over the time period that the pushbutton is held down for a maximum of 12 minutes. This allows the user to traverse large grilles and ducts in one sweep and to have the average value displayed automatically, thereby saving on operator time and inconvenience of manual calculations. The Airhood Kit is used to convert the FloRite® into an air volume flow meter. This kit includes an 11.2" x 9.2" rectangular hood, 7.0" diameter circular hood, protective carrying case, calibration curves and instructions.