This 0.125″ thick clear acrylic with white protractor arc and built-in magnifier allows for precise settings. Thumbscrew knob locks angle in place. Combines functions of a triangle and protractor. Has three sets of graduations: degree, slope, and rise. Use as a drafting square when opened up to 90 degrees. Easily find trigonometric functions using included instructions. Measures approximately 6.25″x 8″x 9.25″.