Stainless Steel Ruler Body- The ruler is made of stainless steel, with precise workmanship, clear scale, CNC machining and comfortable texture. The vertical adjustment knob uses pure copper knurled nuts for easy use. Customers can choose between 200/300/400 mm. There are even two vertical end scales for drawing precision parallel lines from the edge of your work. . Minimum Accuracy 0.25mm- The minimum accuracy 0.25mm makes the operation more precise and reduces errors. The ultra-precise marking rule features tiny holes and slits at each division, allowing you to make a dot or mark a line with a pencil exactly the width of a hair The recessed and black engraved scale is easy to read. . Clear Engraving- Clear and precise laser engraving scales. The imported 0.5mm pen makes the line smoother. The surface is non-reflective, allowing even tired eyes to mark the exact start in low light. Select the appropriate slot or hole, insert a 0.5mm mechanical pencil and mark the measurement with absolute precision. . Multiple Functions- Allows you to get multiple functions, including a horizontal line, a vertical line, a long line, a short line, a parallel line and a right angle line, making your various The shape keeps it perfectly in place, while the dual scale surfaces allow you to mark and measure at the top, edge and corners all at the same time . Suitable for- Suitable for positioning and marking mortise and tenon work for woodworking. The square ruler is just what you need for layout and measurement along the edge of a board or other part. With micro-fine marking holes on each scale line, you can pinpoint your sharp pencil point or trace precisely on target with no uncertainty or eyestrain .