According to relevant projections, by 2010, the annual demand for medium - and large - horsepower tractors is expected to reach approximately 100,000 units, and that for combine harvesters is 50,000 units. In addition, the ownership of various agricultural machinery is also constantly increasing. It is estimated that by 2010, the number of medium - and large - horsepower tractors in use will be around 1.3 million units, and that of combine harvesters will be about 400,000 units. Bearing products account for a relatively large proportion in OEM (Original Equipment Manufacturer) supporting for agricultural machinery. Therefore, the market demand for hydraulic and pneumatic seals for supporting and maintenance of agricultural machinery will increase significantly. Agricultural machinery products require a large number of cylindrical roller bearings, ball bearings, needle roller bearings, etc.