The Starrett Micrometer No. 224 Set AA 0-4" is a high-quality precision tool used for measuring micrometers with a range of 0-4 inches. Made in the United States by the reputable brand Starrett, this set includes interchangeable anvils and standards for accurate and consistent measurements. Ideal for machinists and collectors, this micrometer set is a reliable tool for precise measurements in a variety of industrial and hobby applications.