This is a nice clean beveled solid square with a 3" inside beveled edge. This is a one piece square, not two joined pieces like many less costly precision squares. It has a 2.75" long base and the size opposite the bevel has a slight arc into a smaller bevel on each side of the arc. It is marked "SPI 13-678-8" and there is also a very faint past owner's etch mark in the same area. Condition is very good, no rust only minor finish staining or darkening to report. Inspected to be 0.0002 Inch Accuracy Steel Square.