Premium Material: Made of sturdy aluminum alloy after oxidation treatment, this caliper ruler set is durable, distortion-resistant, practical, rust-proof and corrosion-resistant. Surface: Laser etched metric graduations and the angles on both sides of the miter T rulers are clear and precise, making them convenient and easy to read or make marks during use. Slide to Mark: No need to flip the body when measuring, just slide to mark the right and left angle of 45/90 degrees. High Precision: The square protractor allows you to draw perfect horizontal lines while sliding the ruler along the edge of your work. Measuring, correcting, marking in one product. Application: Thick ruler, makes the ruler stable and precise, perfect for DIY, engineers, carpenters, woodwork and home use.