Features Precise 90 Degree Angles: Both the inside and outside of the Flat Edge Square are precisely set at 90-degree angles, ensuring accurate measurements and layouts. Industrial Grade Tool: Designed for assembly and platform operations, this tool is a reliable and professional choice for engineers, carpenters, and workshop workers. Precision Ground and Lapped: All faces and edges are meticulously ground and lapped for exceptional straightness and parallelism, guaranteeing high-quality results in every use. Enhanced Corner Design: The inner corner features a milled groove to provide clearance for burrs and debris, maintaining smooth and precise functionality. Level 2 Square: Specifically suitable for workshop workers to conduct self-tests, this Level 2 square is a valuable addition to any engineer's or carpenter's tool collection. Accurate 90 Degree Ruler Get precise angles every time with the yunyi Right Angle Ruler. This industrial-grade tool is perfect for assembly and platform operations, with ground and lapped faces and edges for unparalleled straightness and parallelism. The milled groove provides clearance for burrs and debris, making it an essential addition to any workshop. Package List