Made by hardened stainless steel. High Quality 6''(150mm), thumb wheel for accuracy and ease with 4 measurement inside, outside, depth and step. Inch/Metric conversion measurement. Come in a plastic case with foam and oil coated. Range: 0~150mm/0~6” Accuracy: ±0.02mm/0.001” Resolution:0.02mm/0.001” Power: N/A