Spinal Contour Series uses Chiropractic Spring Coil. It is the classical and probably most well-known spring core system. Convex coils have, as the name indicates, a smaller diameter in the center than in the ending coils. These springs are connected in a series attached with helicals. Thanks to the raw materials used and the largely automated production process, an outstanding price performance ratio is ensured. With its special coil form, the Chiropractic Coils core offers progressive spring characteristics.