The dial bore gauge is 0.01mm accuracy, easy to measure. It is used to measure internal dimensions of work pieces by comparative method. Features: The bore gauge is used to measure internal dimensions of work pieces by comparative method. The bore gauge is equipped with a good guiding protective bridge which can be self-centering exactly and reliably. The moveable anvil on one side and an interchangeable on another side , which serves for setting the bore diameters. This is a precision dial bore gauge with a measuring range. Easy to measure, and with high accuracy, which is 0.01. Specifications: Material: Metal Type: 18-35mm / 0.71-1.38in,35-50mm / 1.38-1.97in, 50-160mm / 1.97-6.3in (optional) Package Weight: 18-35mm: 600g / 21.16ounces 35-50mm: 800g / 28.22ounces 50-160mm: 850g / 29.98ounces Package Size: 18-35mm: 270 * 145 * 45mm / 10.63 * 5.71 * 1.77in 35-50mm: 320 * 145 * 50mm / 12.6 * 5.71 * 1.97in 50-160mm: 320 * 160 * 50mm / 12.6 * 6.3 * 1.97in Packing List: 1 * Dial Indicators 1 * Extension Rod 1 * Set of Measuring Heads 1 * Box