brand new and high quality Features: For checking the squareness of an edge, using the light-gap method; The blade is bevelled on both sides,30 degree edge Square is true right angles both inside and outside Beams and blades are ground and lapped for parallelism Machinist square supplied in a sturdy protective for case 1.For checking the squareness of an edge, using the light-gap method. The blade is bevelled on both sides. 2. Accuracy grade 1, squareness tolerance of 0.02-0.05 mm. 3. Supplied in a protective for case. 4. Beams and blades are ground and lapped for parallelism. 5. 30 Knife edge, beams and blades are ground and lapped. specification: Size: 80x50mm/125x80mm/63x40mm Edge angle: 30 for Seat Width: 5mm Accuracy: Grade 1 Tolerance 0.02-0.05 mm Use For: 90 right angle measuring, designed for precision layout and measurement work. Color:sliver Material:stainless steel Quantity:1pc Note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1x 90 Degree Right Angle Ruler