Angle Measurement Tool:2 in 1 with our clever idea of converging goniometer and ruler into a double scale from 0 to 180 degrees, measuring lengths from 0 to 15 centimeters. Protractor material: Polished stainless steel, brass locking nut. High quality stainless steel material resistant to durable work. Exquisite. Professional tool for drawing or measuring angles or lines. For drawing radial lines, setting bevels and transmitting angles. Adjust the suction cup by loosening the screw. Used to draw radial lines, skew and translate angles Protractor ruler alarm and dial head can be disassembled; perfect for school, business, home, mechanical work, woodworking, etc. Description: The protractor is made of sturdy stainless steel, permanently etched, durable and long lasting. Double division of 0-180 and 180-0 bi-directional mark and scale mark on bottom edge of semi-circular dial head. This protractor ruler has a 150mm adjustable straight ruler, which can be held in position with the knurled lock nut and can detect angles quickly and easily. The protractor of ruler is suitable for chamfering, drawing radial lines, measuring and marking angles. The protractor ruler alarm and the dial head can be disassembled; perfect for school, business, home, mechanical work, woodworking, etc. specification: Material: stainless steel < p>Measurement: Double graduation from 0-180 180-0 degrees in two directions; 150mm/6" Protractor Ruler Use: Adjust bevel, draw radial lines, measure and mark angles Applications: school, commercial, home, mechanical and woodworking applications, etc. Size: 150mm, 0-180 degree rotation Package includes: 1 Protractor, 0-150mm Note: The data is manual measurement, please understand. please allow 1-123cm error, due to differences between light and screen, there will be a certain color difference, the specific received in kind prevail.