Its open design with large clearances e ectively prevents blockage even when working with high contents of organic matter. The serrated concave discs (510-570-620 mm diameter), which are supported by maintenance-free angular ball bearings, form the basis for the outstanding quality of work produced by this highly durable implement. The concave disc beams, which are located inside closed pockets and feature robust coil springs to protect them against overloads, ensure precise disc guidance even under diffcult conditions. An impact harrow, which can be individually and finely adjusted, is provided behind the two rows of discs for precise deposition of the flow of soil. This improves the distribution of straw when driving at a diagonal angle to the direction of threshing.