Hardened stainless steel 4-function measurement: internal, external, depth & step Thumb wheel for fine adjustment Large, easy-read screen Metric & imperial measurements to 0.01mm/0.0005" accuracy Quality, stainless steel digital vernier calipers with 4-function measurement: internal, external, depth and step. Thumb wheel fine adjustment and zero setting at any position. Large, easy-to-read display. Accurate to 0.01mm/0.0005".