<p>reduces errors. Ultra-precise T-ruler has small holes and grooves on each grid, this T-ruler can draw lines exactly where you want, perfect for woodworking and a good helper for you. The scale marking ruler with holes is made of high quality stainless steel and PF, which is high precision, rustproof, stable and durable. The Stainless Steel Combo Square T-Ruler features deeply etched graduations for excellent readability and long-lasting use. The smooth, flat back allows you to easily move the T-ruler. Plus, it has permanent deep markings and graduations for maximum readability.Choose the appropriate slot or hole and use the mechanical pencil to mark on the ruler to make the line smoother. The non-reflective surface marks the exact starting point even in low light conditions. Also comes with a removable knob, allowing you to easily swap other rulers. Easy to install and change different rulers. This precision T-type marking ruler is widely used, allowing you to draw horizontal lines, vertical lines, long lines, short lines, parallels, right angles and precise . The positioning is precise, and the two graduated surfaces allow simultaneous marking and measurement of edges and corners.</p> <p>Note: The data are all manual measurement, please allow an error of 1 - 3cm, due to the difference in light and display, there will be a certain color difference, depending on the physical object received.</p>