... .wide varieties 1.6000, 6200, 6300, 6400, 6800, 6900 and 16000 series2.inner packing:plastic bag,tube in carton3.less ... coefficient of friction, high limiting speed,4.large size range and colorful combination of structure; 5.used in tactors, motors, automobiles, ... motorcycles, and other common machinery, as a widely used type of ...