It has two parts: cleaning and de-stoning:  Cleaning part removes all materials that deviates from the size of the grain  kernel like straw, strings, small seeds which are light and effectively  extracted by sieving. De-stoning is mainly to remove any additional stones. Efficient cleaning, high output, easy operation, good appearance, stable  performance, low consumption, light weight, low noise and no dust pollution.  www.ricemachinechina.com