Great device. The only downside I found was the teeth that bent when I tried to use it. I recommend slacking off the tension on the teeth to allow the plastic teeth to move faster. You can then attach the piece to the measured shape.
Pros
π Useful Contour Gauge --- Also known as a profile comb or shape duplicator, is a tool for plotting the shape of a cross-section of a surface, consists of a set of pens made of high quality ABS plastic, installed close together in a frame, which keeps them in the same plane and parallel, allowing them to move independently perpendicular to the frame. The contour copy tool is perfect enough to copy any shape for easy transfer to tiles and other surfaces