Major Tech digital caliper features gearless operation, and displays measurements on a digital readout. They also feature zero set controls, on and off, inch, and mm control buttons, and they display decimal inches, fractions, and metric graduations. They are designed to measure both inside areas and outside areas of objects using upper and lower jaws. Features : Selectable mm or inches with zero adjustment function Measurement length – 150mm with resolution of 0.01mm 1.5V Silver oxide battery supplied included