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