Description: Measurement range for 0-150mm/ 0-200mm/ 0-300mm, resolution of 0.02 cm Used to measure the depth or height of step and the depth of the groove Vernier scale for precise measurements in fine units, precision tool for a professional machinist/tool maker Made of stainless steel, and base/ measuring faces are hardened and lapped Has fine adjustment screw for precise measurements Specification: Material: Stainless Steel Width: 10 cm Length: 23/ 28/ 38 cm When measuring the depth of the inner hole, first the end face of the base should be abutted against the end face of the hole to be measured, so that the guage body is parallel to the center line of the holes; then dip into the ruler body. Finally The distance between the end of the ruler and the end face of the base is the depth of to be tested. The reading method is exactly the same as the vernier caliper. Package Includes: 1 Piece Metric Vernier Depth Gauge Note: For multi-step and small diameter bore depth measurements, it is important to note whether the end face of the ruler is on the step to be measured. When the reference plane is a curve, the end face of the measuring base must be placed at the highest point of the curve. Otherwise errors will occur. Metric reading only.