Specific Range for Precise Applications: Contains 125 pieces covering sizes from 0.501" to 0.625", tailored for precise measurement tasks requiring specific range accuracy. Class ZZ Standard Accuracy: Complies with Class ZZ standards, featuring tolerances of +0.0000" / -0.0002" for minus sets, ensuring high precision for critical measurements. Durable and Smooth Operation: Each gauge is heat-treated to HRC 60-62 and boasts a 10 microfinish or better, providing durability and a smooth measurement interface. Effortless Identification: Gauges are electro-etched with their actual size, facilitating easy and accurate selection for efficient use in various tasks. Uniform and User-Friendly Design: All gauges maintain a 2" length and are centerless lapped, ensuring consistency and ease of handling across the set.