High-precision steel gauge block: Made of premium steel with high hardness and wear resistance for stable measurement. Square block design: Sharp edges for accurate vertical and horizontal calibration. Compatible with various tools: for calibrating calipers, micrometers, depth gauges, and more. Precision ground surface: Excellent finish with tight tolerance, suitable for lab and industrial use. Custom sizes available: Non-standard dimensions can be tailored to meet specific inspection needs., Manufacturer: ZKLGS