This pen blank center finder is designed to draw 45 degree lines on small-sized material, such as cuboid, cube, cylinder, rectangular, square or round timber. Draw the center line of the circle easily for the cylinder. Easy to use, just putting it onto the wood and then drawing 2 lines to obtain centerlines. Machined to exacting tolerances, durable, will lasts for years. Made of high quality aluminum alloy material through oxidation treatment, this 45 Degree angle marker is durable and sturdy, unfading, rust resistant and wear resistant.