specific granite stone roller: it is the first-class granite in the world, the granite used in this stone roller is a pure natural magma formed by a volcanic eruption. This kind of stone has high density, anti-magnetic, anti-vibration, and high-pressure resistance; the line pressure can reach 350KN/m; each cubic meter is 800 kg heavier than ordinary granite; the color is blue-black, high acid and alkali resistance, no metal, and uniform particles, never fall off; can increase pressure on wet paper, good dehydration, easy to lead paper, easy to peel, easy to dry, not easy to break the paper. It can produce high-quality paper products with high tensile strength and high surface smoothness, which are favored by users all over the world.