1、The vernier caliper is made of stainless steel, with high hardness, corrosion resistance and not easy to wear. 2、The tightness of the tightening screw can be adjusted at will to fix the caliper body and achieve more accurate measurement. 3、Adopts a fine‑tuning roller design, which can be supported by the thumb, and the operation is more stable and smoother. 4、The ruler body is processed by laser, and the scale surface has clear lines to ensure the accuracy of the measurement. 5、The vernier caliper is mainly used in the industrial field to measure the outer diameter, inner diameter, hole depth and step size. 1 x Vernier Caliper Item Type: Vernier CaliperMaterial: Stainless steelMeasuring Range: Approx. 0-200mm / 0- 7.9inResolution Value: 0.02mmHow to Use: Take the reading of the external measuring surface as an example. First find the 0 scale line of the secondary ruler, read the main ruler scale on the left, find the place where the main ruler and the secondary ruler scale are completely aligned, read the reading of the secondary ruler, and finally follow the precise reading formula "Main ruler reading + secondary ruler reading x secondary ruler accuracy = accurate measurement value" just read the value.