Jackson Safety Contour Radius Marker (14782), Standard, Aluminum, Up to 24 Inches Radius, 1 Unit/ Order 1 Jackson Safety Standard Radius Marker / Order Made of durable, lightweight aluminum, comes with a soapstone crayon Marks circles up to a 24 inch radius Also available in mini, small and jumbo (this model is Standard) Sturdy friction joints to help maintain rigidity and accuracy in marking