Specifications:Material: FiberglassColor: Silver Measuring Range: 0~150mm / 0~6"Resolution: 0.1mm, 0.01"Accuracy: 0.3mm / 0.011"Repeatability: 0.1mm / 0.01"Max. Measuring Speed: 1.5m/sec, 60"/sec Measuring System: Linear Capacitive Measuing System Displa: LCD Display Power: 1 * SR44/LR44 1.5V Button Battery (Not Included) Working Temperature: 0~40 Centigrade Degrees / 32~104 FahrenheitInfluence of Humidity: Not important under 80% of relative humidity.Product Size: Approx. 23.7 * 7.5 * 1.3cm / 9.3 * 3.0 * 0.5inProduct Weight: Approx. 54.1g / 1.9ozPackage Size: Approx. 28.5 * 10.2 * 2cm / 11.2 * 4.0 * 0.8inPackage Weight: Approx. 83.8g / 3.0oz Features:Large LCD display for easy reading.Zero setting at any position.Manual power on/off.Linear capacitive measuring system, accurate.Metric/inch units interchange.Suitable for measuring jewelry, paper, magnetic products.Suitable for measuring the inside diameter, outside diameter and depth.Basic Measuring Methods:1. Loosen the locking screw. 2. Switch the unit on with a press on "ON" button. The select the unit system needed by pressing "mm/inch" button. (Each time the button is pressed, inch and metric digits will be displayed alternatively) 3. Apply normal measuring pressure on slider to close the external measuring jaws. Then press "zero" buttom to reset the display to zero. 4. Can measure internal dimensions, also can measure external dimensions.