The Kjb-05 Electric-Magnetic Field Tester is a portable instrument designed for detecting and measuring both electric and magnetic fields. It provides readings in easy-to-understand units, allowing users to assess potential exposure to electromagnetic radiation. Its compact size and user-friendly interface make it ideal for both professional and home use. The device may include features such as a digital display, data logging capabilities, and multiple measurement ranges. (Note: This description is hypothetical as I have no access to the actual product specifications).