Digital Readout Linear Metric Imperial Scale Dual Purpose Linears Scale for LathesRound 0-1000mm Item Type: Digital Readout Linear Material: Stainless Steel + Aluminum Alloy Scale Unit: Metric Scale, Imperial Scale ABS Key: Relative Measurement Absolute Measurement Conversion SET Key: In the inch measurement state, each time you press this key, the resolution of the fractional part will switch between 1/3, 1/64, and 1/128 in mm Key: Metric Inch Conversion at Any Position ON OFF Key: Power Switch Key ZERO Button: Reset Button at Any Position Response Speed of Moving Grid Sensor: 3 Meters/S Specification(mm) Battery Resolution(Approx.) Accuracy(Approx.) a(Approx.) L(Approx.) Round 0-1000mm  3V CR2032 x 1 Button Battery 0.01mm/0.0005in ±0.2mm/0.008in 1124mm/44.3in  1148mm/45.2in Square 0-1000mm  3V CR2032 x 2 Button Batteries 0.01mm/0.0005in ±0.2mm/0.008in 1124mm/44.3in  1148mm/45.2in