Here are some of the features and specifications for the Testo 865 thermal imager:

1. Resolution: The device has a resolution of 160 x 120 pixels. This means that the thermal image consists of 19,200 individual temperature measurement points, giving a relatively clear image for identifying temperature discrepancies.

2. Temperature Range: The Testo 865 can typically measure a broad temperature range, suitable for a variety of applications.

3. Display: The imager usually comes with a clear display that shows the thermal image, making it easy for the user to identify hot or cold spots.

4. Automatic Hot/Cold Spot Detection: This feature can automatically identify the hottest and coldest points in an image, which can be helpful during inspections.

5. Ease of Use: Designed for straightforward operations, it typically offers intuitive menus and easy-to-navigate interfaces.

6. Durability: The design often focuses on ruggedness and can handle the wear and tear of field operations.

7. Image Storage: Users can store thermal images for further analysis or reporting.

8. Software Compatibility: The device usually comes with compatible software that allows users to analyze images on a computer, create reports, and more.

9. Emissivity Settings: Depending on the surface being measured, the emissivity settings can be adjusted to provide accurate temperature readings.

10. Extended Battery Life: For prolonged field usage.

The Testo 865 thermal imager is a tool aimed at professionals who require thermal imaging capabilities, whether in the construction industry, electrical maintenance, HVAC diagnostics, or other fields where heat patterns are crucial for diagnostics and preventative measures.