Alvin Rolling Parallel Ruler

The Alvin Rolling Parallel Ruler is a multi-functional tool that accommodates a wide range of measuring and drawing applications. It allows drawing of vertical and horizontal parallel lines with ease and accuracy. With its built-in protractor, it can be used to draw circles, curves, and arcs. It can create circles with diameters of up to 12 inches (for the six-inch ruler) and 24 inches (for the 12-inch ruler).