-precision gauge block set: Designed for calibrating calipers, micrometers, and other precision measuring tools. Versatile size combinations: Includes commonly used lengths with stackable options for flexible measurement tasks. Premium hardened steel construction: Ensures excellent wear resistance and long-term dimensional stability. Complies with ISO 3650 standards: Each block is finely ground and mirror-finished for repeatable accuracy. for professional applications: Widely used in machining, making, inspection labs, and metrology calibration.