Hardened stainless steel frame and measuring jaws Thumb roll & knurled locking screw for more convenient measurement and reading Relative/absolute measurement interchange at any position(abs function) Glass fixed grid, stable and high accuracy Quick display of the measured value on lcd screen With on-off power switch & auto power-off for option Waterproof ip54 Four function key With depth bridge Zero-setting at any position Mm/inch measurement system conversion 3v environmental battery, battery life >1 year Measurement both for id, od, depth, and steps Part no.Measuring range(mm/inch) Resolution(mm/inch)Accuracy (mm/inch). Plastic box with froam inside, then carton box, then master carton