The CG104 Coating Thickness Tester is a portable, one-handed instrument designed for quick, non-destructive measurement of coating thickness on ferrous and non-ferrous substrates. It employs dual technology with automatic substrate recognition: magnetic induction for ferrous materials (iron and steel) and eddy current measurement for non-ferrous materials (copper, aluminum, zinc, bronze, brass). The device features a 180° reversible LCD display for convenient readings at challenging angles, a measuring range of 0 to 2000 µm (0 to 80.0 mils) for ferrous substrates and 0 to 1000 µm (0 to 40.0 mils) for non-ferrous substrates, with 1 µm resolution. The CG104 is widely used in automotive paint inspection, quality control of anodizing and galvanizing processes, and by paint manufacturers, inspectors, and anti-corrosion contractors across machine tools, pipeline, and aeronautical industries.