Specifications: Display mode: four digit LCD display Minimum display unit: 0.1mm Measuring range: 1.2-220mm (steel) Measurement error: (1% 0.1) mm Sound speed adjustment range: 1000-9999m/s Lower limit of pipe measurement: 10mm Probe: 20 * 3mm (steel) 6mm probe: 12 * 2mm (steel) Operating frequency: 5MHz/2.5MHz Operating temperature range: 0-45 & 8451; Power supply: 5V battery * 3 Working current: normal test 50mA, LED backlight 120mA, static current mA Reverse sound velocity measurement function: Data storage function: Low current indication:. Automatic shutdown function: Product size/weight: 159 * 63 * 33mm/175g Packaging method: color box packaging