SPI Plastic Dial Caliper Model 31-415-3

Makes inside, outside, depth, and step measurements up to 150 mm. The metric dial is graduated to the nearest 0.1 mm. The ruler is graduated out to 6” in 16ths. Accuracy to ±0.0015 mm. Dial may be turned to adjust caliper to “zero reading” before measurements. Thumb roller rolls to the left for outside measurements, to the right for inside measurements. Sturdy plastic construction.