Acu-Arc Adjustable Ruler Metric Measure & Draw Curves Radii 17cm to 500cm

Acu-Arc Ruler Centimeter: A ruler that eliminates the need for a beam compass or expensive curve sets. It can be adjusted to any radius, from 63/8" to 200" (17cm to 500cm), to determine the radius of an existing curve for dimension drawings, to find center lines and center points, or determine what a curve must be to fair in existing points, or lines, on a drawing.