The Extech 380947 is a 400-amp True RMS tiny clamp meter. This meter has a tiny diameter jaw that can reach into confined spaces while delivering 1mA resolution and very low-current sensitivity. This tiny clamp meter can be used to troubleshoot current and frequency issues in plant maintenance, electrical, HVAC, and telecom work, as well as residential electrical, fleet maintenance, marine, and motorcycle repair. Includes battery and instructions.