... durability of bearing seal.Main Type Available Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 ... performance.Main Type AvailableSize: 5 7/8",6",6 1/2",7 1/2",7 7/8",8 1/2",9 1/2",9 5 ... the probability of cone-dropping to minimum.Main Type AvailableSize: 8 1/2",9 1/2",9 5/8",9 7/8",10 ... which reduces the probability of cone Cdropping to minimum.Main Type AvailableSize: 2 3/8",3",3 5/8:",3 7/8 ...