Adjustable Precipitatior Arm: features center positioning and scribing, and a knurled nut that adjusts the protractor arm to quickly and accurately identify angles and draw straight lines by locking the nut in the desired position. Useful for setting bevels, drawing radial lines, measuring and marking angles. Angle Ruler: construction protractor with both length and angle measurement functions, with an adjustable thumb nut. After tightening, you can easily measure 0180 degrees and read the angle. The angle ruler is clear and accurate and can measure length from 08 inches. Suitable for professionals and DIY users in carpentry, construction and engineering. Protractor: the body is made of stainless steel with laser engraved measurements for clear readability and durability. With a thickness of 2 millimeters, the ruler is sturdy and solid. If you need an exact, sturdy angle measuring tool for your home, this woodworking protractor fits the bill. Please note: slight color variation or difference in kind may occur, but this does not affect use. Practical applications: 1) Set bevels and draw precise radial lines in woodworking and furniture making. 2) Mark angles on circular parts, gears or wheels and lay out radial patterns accurately. 3) Quick onsite angle and length checks for carpentry, construction and engineering projects.