The new carpentry edge ruler simplifies your life by wrapping around the edge of inventory and providing precise proportions on both sides. The secret to the T-shaped square is a series of indexing holes precision machined and close tolerance spring loaded indexing pins engaged with it. The pin snaps into place, giving you confidence that it is precisely positioned. Even the most experienced woodworker faces the challenge of placing the angle precisely on a large panel project. You can try to extend the production line from a small protractor, but even a small error will cause the production line to extend further, the bigger the error. Our latest precision ruler can provide unparalleled precision for your panel layout work. Simply press the head to the desired angle, then press the straight line. The head can be adjusted from 0 to 70 and is firmly locked every 5 (plus 22 -1/2 and 67-1/2) to provide you with precise reference angles and lengths respectively. It measures 10 inches, 15 inches, or 20 inches. Even if you don't use angles, this is a layout tool that can be used in almost any project. The blade has the same exclusive serration function. Design notches are found in our new product. Stainless steel precision woodworking square. There is a notch every sixteen inches across the entire blade. Simply place the pencil in the notch and slide the head along the edge of the stock for the perfect parallel line. Product Features: The new carpentry edge ruler simplifies your life by wrapping the edge of inventory and providing precise proportions on both sides. The secret to the T-shaped square is a series of keyholes. precision machined indexing pins and close tolerance spring loaded indexing pins engaged with it. Our latest precision ruler can provide unparalleled accuracy for your panel layout work. Simply press the head to the desired angle, then press the straight line. The head can be adjusted from 0 to 70 and is firmly locked every 5 (plus 22 -1/2 and 67-1/2) to provide you with precise reference angles and lengths respectively. It measures 10 inches, 15 inches or 20 inches. Even if you don't use angles, this is a layout tool that can be used in almost any project . s: Material: metal Color: silver Size: 20 inch Measuring range: the head can be adjusted between 0~70 Package including 1 * woodworking edge ruler< /p>