The Starrett 20-4 1/2 Master Precision Square is a high-quality tool for metalworking inspection and measurement. Made in the United States by the reputable brand Starrett, this master precision square is a reliable and accurate instrument for ensuring squareness in various metalworking applications. With a strong reputation for durability and precision, the Starrett 20-4 1/2 square is a tool that is highly sought after by professionals in the CNC, metalworking, and manufacturing industries.