Our dial calipers are made from hardened stainless steel, Swiss Watch precision gears, covered rack and shock proof to produce accurate and consistent readings for years to come. All mechanical, no batteries needed. metal Imported Dial face reads in both inch (black) and metric (red). Hardened stainless steel throughout. Inside, outside, step and depth measurement. Raised sliding surface prevents wear and defacement of graduations. Covered, stainless steel rack.