... .Main Type Available Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8 ... seizure resistance of the bearing are improved. 2.Premium O-ring, Optimal seal compression and curved seal structure can ... cone-dropping to minimum.Main Type AvailableSize: 8 1/2",9 1/2",9 5/8",9 7/8",10 5 ... /8",4 3/4",6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/ ... 8",12 1/4",15",15 1/2",17 1/2", etc. IADC Code:5-- Series,6 ...