1) Measuring range (metric/imperial): 1.2-225mm,0.05-9inch 2) Operating principle: ULTROSONIC 3) Materials measured: any hard materials, including steel, cast iron, aluminum, red copper, brass, zinc, quartz glass, polyethylene, PVC, gray cast iron, nodular cast iron and other materials 4) Sound velocity: 500-9000m/s 5) Calibration block: included 6) Resolution: 0.1mm 7) RS232C interface: with RS232C 8) Power supply: 4x1.5V AAA (UM-4)battery 9) Battery indicator: low battery indicator 10) Dimensions: 120*62*30mm 11) Weight: 164g(not including battery)