Premium Material: Doesn't scratch your precious items when measuring, you will serve for years. Accurate Reading: Rigorously tested to ensure accurate readings of 0.04 cm. Zero Calibration: Press the button to zero at any position and continue to measure the next section. Unit Conversion: Easy to read inches and mm by pressing the blue button on the top. Large LCD Display: Shows instant measurements with digital numbers, much more convenient. Auto On/Off: Automatically turn on when sliding and automatically turn off after 5 minutes if there is no operation. 4 ways to measure. - External measurement: Measure the outer diameter of objects with the long jaws. - Internal measurement: measuring the inside diameter of objects with the upper jaws. - Depth measurement: measure the depth of small objects that are difficult to reach with the long probe. - Height and length measurement with its step design. Features: Material: carbon fiber composite. Dimensions: 23.9 x 7.6 x 1.5cm. Weight: 56.7g. Measuring range: 0-150mm. Precision: ±0.2mm. Resolution: 0.1mm. Battery: LR44 1.5 V button battery. Contents: 1 digital caliper. 2 batteries (one in the bracket, the other in the package). Warning: 1. Before first use, please remove the white insulation strip in the battery cover, otherwise the electronic caliper cannot work. 2. The digital caliper is only for household measurement, such as jewelry, gadgets and other household items. If for industrial measurement, please purchase a more professional and more accurate measuring tool in the professional field. 3. If you find the measurements are not accurate, please slide the LCD to the far left (“0” on the scale), then press the zero button. Do not hesitate to contact us for more questions. <ul><li> Batteries </li></ul>