Features of a 45 and 90 degree adjustable triangle plus those of a protractor, Angles from Zero to 90 degree, can be drawn from the baseline with , 5 inch accuracy, Die-engraved graduations for high visibility, The aluminum thumbscrew securely holds the selected angle and allows quick pickup and manipulation, Made of high impact, 0, 100 inches thick, optically clear acrylic to eliminate parallax and allow close pencil tolerance, SKU: ALV5936