Bearing is an important component which has great influence on the casters load capacity, rolling flexibility and service life. The commonly used bearing is roller bearing, ball bearing and Delrin bearing. They perform well in different environment. For example, roller bearing does well in bear load, but is not so excellent in rolling flexibility. Ball bearing does otherwise. The baring material also should be taken into consideration, stainless and Delrin bearing does well in anti-corrosion and widely applied in the moist environment. The more details about their advantages in different environment are introduced in the each product description.