Chartpak 6180 Protractor, Acrylic, 6" Ruler Edge, Transparent Tinted CHA6180 CHA 6180, Beveled edges and 1/2 graduations provide accuracy. Measurements up to 180 Transparent plastic is easy to read on colored paper. Engraved and scratch-resistant surface. Distortion-free. Degree Graduations: 1/2; Material(s): Acrylic; Ruler Size: 6" Ruler Edge; Color(s): Transparent Tinted., UPC 014173156860