The Weldmark by CurvOMark Medium Wrap-A-Round pipe ruler is an easy to use tool designed for pipe fitters and welders as an economical measuring tool for marking straight lines around pipes or to mark a straight edge prior to welding or cutting. Made from flexible gasket martiral that is asbestos free and resistance to cold and heat up to 350 degrees Fahrenheit. Designed for 3 to 6 inch pipe diameters and are printed with a scale in inches, inch chart, tangent chart, and other useful markings.