Designed and built by Ray-Ran, the Cold Flex Tester determines how low temperatures affect the torsional stiffness properties of flexible materials, including polyvinyl chloride extrusion compounds, by measuring the temperature at which a test specimen is twisted through a known angular displacement using a pulley system by a specified torque. The apparatus complies with BS2782: Part 1: Method 104B, ISO458/1, 458/2 and ASTM D1043 International Test Standards.