TSI AirPro VT-A Velocity Temperature Articulated Probe for AP500 Velocity Meter is for use with the TSI Air Pro AP500 Velocity Meter. The TSI AirPro VT-A attaches to the AirPro AP500 and measures air velocity and temperature with articulation and the ability to be extended with 800529 Probe Extension. The TSI VT-A is 12 inch in length and measures air velocity from 30 ft/min to 6000 ft/min and temperature from 14°F to 150°F (-10 to 65°C).**Requires TSI AirPro AP500**