The Starrett No. 124-B Inside Diameter Micrometer Set is a high-quality tool designed for precise measurements of internal diameters. Made by the reputable brand Starrett in the United States, this set includes a .500in insert for measuring sizes ranging from 2 to 12 inches inn half inch increments. With a resolution of 0.00100 inches, this micrometer provides accurate readings for a variety of industrial and manufacturing applications. Ideal for metalworking inspection and CNC processes, this inside micrometer set is a reliable and essential tool for professionals in the field.