The Checkline JD-50R Digital Thickness Gauge is used for measuring running materials like tapes, wires etc. It has the benefit of an easy to read LCD display, combined with the highest accuracy. The user can select either to display thickness in mm or in inches. Ball bearing mounted cylindrical rollers, in lieu of flat anvil surfaces, make these dial micrometers ideal for measuring the diameter or thickness of slowly moving wire, filaments, foils, ribbon, narrow fabrics, etc. - without stopping the manufacturing process.