Thermo-Anemometer with Automatic Temperature Compensation and Telescoping Probe The AN500 is a Hot Wire CFM/CMM Thermo-Anemometer. This Thermo-Anemometer comes with Automatic Temperature Compensation and a Telescoping Probe. New sensor technology delivers major improvements in durability and ATC (Automatic Temperature Compensation) for accurate in-duct Air Velocity measurements with changing air temperatures. Its telescoping probe with ruler label ensures that measurements are made in the center of the duct even if it is out of reach. Ergonomic directional handle and anti-rotation sensor confirms that probe direction and airflow direction are aligned for confident readings. Complete with telescoping probe with cable, 100 Volt to 240-Volt AC Universal Adaptor with 4 plugs, 6 batteries, and hard carrying case.