Electronic digital calipers, provide easy, fast, error-free measurements, plus SPC (Statis tical Process Control) analysis and documenttation. These instruments are battery or solar operated and except for the moveable jaw, have very few exposed mechanical parts. A button permits the user to choose inch or metric measurement, which can be read from a LCD digital readout. Inch measurements are displayed to within .0005 in. and metric to within 0.01 mm..