This dual-purpose ruler also works as a compass, allowing the you to make circles from 1/16" to 12" in diameter. It's a useful tool for draftsmen, students, artists, and crafters who require precise, measured lines.Details:Clear and green12" (30 cm) ruler sizeFeatures nine circle stencilsGreat for mathematic calculations, technical drawings, and designing patternsGraduated in both imperial and metricPlastic