Professional Multi-Ruler 360 Degree Goniometer Angle Medical Spinal Ruler cm/inch. Two rulers organize in one body, with multi scale cm/ inch/ angle/ parallel line on ruler make this ruler can be used in many area. Using special printing technology, the scale will not wear by long-term used. Designed to measure axis and range of motion. It is a good tools for hospital, pharmaceutical or medical supplies as well as a for normal usage, used for measure the movement range. of joints such as elbows, knees and fingers, also can be a general length measuring tool.