These color-coded mil gauges are solid anodized aluminum for long life and come in four sizes for a variety of FRP applications. Machined to close tolerances (0.0001?) for accuracy and available in mils (inches) and microns (metric).
Ответ:They are wet film gauges. For measuring wet film thickness of paints, enamels, lacquers, adhesives & many other wet coatings that are sprayed, dipped or brushed on a smooth surface.