... bearing are improved and suitable for high rotary speed. 2.The advanced metal seal package will improve the reliability and 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 7/8",12 ... /8",4 3/4",6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8",12 ...