Made of premium stainless steel, good strength with stable characteristics and high reliability. Depth dimensions can be measured easily and accurately. '0' setting in any position, mm/inch measuring system conversion. Quickly displays the measured value on the screen, no overspeed error. Digital calipers for easy, direct and clear reading. Less accurate error, more accurate reading. Digital direct reading, can quickly return to zero, clear and convenient, accurate measurement. Made of high-quality stainless steel, it is not easy to rust and extends the service life. The scale is delicate and clear, the usability is high, the main ruler has careful workmanship, firmness and durability, and long service life. The attached conversion table is convenient for conversion, used for depth measurement, groove width measurement and groove position size. The nut is rotated to adjust the tightness, which can be fixed and measured, and can be used flexibly. One-touch conversion, zero at any position, more convenient and efficient measurement. Button battery, convenient and fast, long battery life. Zero method First, wipe the measuring surface of the ruler frame and the measuring surface of the ruler body, find a smooth and flat plane, make the measuring surface of the measuring claw contact the plane, and the observation reading should be zero. If it is not zero, press the zero button to clear it. Metric/inch system: It is more convenient to convert with a metric and English comparison table, and it is more convenient to measure with inch pressure. Easy to read: digital caliper, fast reading, convenient display, direct and clear. Large capacity battery: Longer battery life: Uses 2 LR44 batteries (not included), large capacity, strong performance and longer battery life, reducing the trouble of frequent battery replacement. Easy to carry: Small size, light weight, easy to carry