This document introduces the safety warnings, features, specifications, and instructions for the multi-function tester MODEL 6020/6030. This tester has five-in-one functions including voltage measurement, insulation resistance measurement, ground resistance measurement, phase detection, and phase sequence detection. It is suitable for measuring and maintaining distribution systems or electrical equipment with a rated voltage of 600V AC/DC. The tester features waterproof design, easy-to-read wide-screen display, automatic shutdown, and backlight function.