Features of Heat Index and Airflow Anemometer Extech AN25: Displays minimum, maximum, and average values over selectable intervals of 5, 10, or 13 seconds for accurate trend analysis. Allows you to freeze the current reading on the display for easy viewing and recording. Conserves battery life by automatically turning off after a period of inactivity, with an option to disable this feature when needed. Features a detachable impeller for quick and easy replacement, ensuring long-term reliability and consistent performance. Supplied with a CR2032 battery, ready for immediate use right out of the box.