Before 2005, the wide belt sanders in china are mainly calibrating sanders, the sanding units are mainly sanding roller units and sanding pad units. The sanding pad is solid pad, not segmented pad. The configuration is basically single belt roller type, twin-belt roller and pad type, three belt roller roller roller type or roller roller pad type. Also, some factories in china build double surface sanding units in a single body, the sanding units are similar with above mentioned.