It is specially meant for upgrading of the product quality i.e. Seed/Grain etc. by separating the impurities on the basis of the difference in specific gravities which are otherwise of the same shape &size. The impurities which are of the same shape & size of the required quality product but having different specific gravity cannot be separated by Air Screen Seed Cleaner (Seed Graders), Length separators because these machines work on the principle of separation (grading) on the basis of difference in physical parameters like shape & size etc.