Sufficient Lot - Total 17 pcs measuring rulers, 17 sizes, enough to meet your daily use and measurement needs Detailed Dimensions- Measuring Ruler: 70x11.5x2.5mm/2.76x0.45x0.09 Inch, hole Diameter: 5mm/0.19 Inch. Circle: 55x6mm/2.16x0.24 Inch, inner Diameter: 51mm/2 Inch Unique Design- Corner design with dimensions printed on the top, nestles nicely between the desktop and the machine. You can use a round ring to hold the round hole in series, favouring storage Easy to Use- Simply pick up your ruler, select your desired working focal length, place it on the material, and then lower the laser head to the desired focal length Focus Tool- A good solution to the problem of not being able to see small numbers or not being able to focus accurately when using the focus tool that comes with the laser