Features: 1.Micrometer Unit: Paint thickness tester has a color scale in microns, used to measure the thickness of varnish coatings with an accuracy of 20 microns. 2.Purpose: Used to detect the paint coating thickness invisible to the naked eye on vehicles made of steel and galvanized steel. Quickly and accurately check whether the vehicle was painted in the past. 3.How It Works: The thickness of varnish and putty is measured by touching the tip of the tester with the magnet on the surface to be tested (the surface must be clean and dust free). 4.Magnetic Tip: Paint thickness meter uses a magnetic tip, it can stick to any curved surface or hard to reach place, which is very helpful. 5.Advantage: No need for battery power supply, fine workmanship, waterproof, high precision, high reliability and easy to use. Specification: Item Type: Paint Thickness Tester Material: Metal+ABS Color Representation: Blue: 0.0 to 100 microns thick coating---a thin layer of varnish (the varnish has no foundation or repeated polishing) Green: The coating thickness of the original varnish is 100 to 200 microns. Warning; in newer models, a thickness of 180 microns may indicate a thin layer of second varnish. Yellow: The coating thickness is 200 to 300 microns---after spray paint repair (secondary varnish). Red: a coating with a thickness of 300 to 520 microns---the surface after the sheet metal repair + the second varnish. Black: The coating thickness exceeds 520---surface putty and varnish (the amount of putty is about 0.5mm). Application: Generally used for second hand cars to detect paint thickness, all cars can be used