General Tools Vernier Calipers deliver the accuracy and precision you desire without cutting into your budget. The solid steel design provides a range of 5” and can take outside, inside and depth measurements. The smooth-action thumb roller allows you to dial in on the correct measurement by advancing and retracting the slide with precision. There is also a frame lock for taking repetitive measurements. This high-quality vernier caliper provides both Metric and English readouts as small as 1/128” (.1mm), and the slide bar is graduated in 1/16” and 1mm increments.