Johnson Level & Tool 1887-0000 Digital Depth Gauge, 3-1/8 In, 80Mm
It has a range of 0 to 3-1/8 in /0 to 80mm and its resolution is 0.002 in/0.05 mm. This digital depth gauge has a 4 in base length and full base style, making it easy to slide under an object when needed.