... seal.Main Type Available Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8 ... conewhich reduces the probability of cone-dropping to minimum.The HH Tricone bit Series reduces sound to a maximum of 60 ... up to 120 decibels. Main Type Available Size: 8 1/2",9 1/2",9 5/8",9 7/8",10 5 ... TCI Tricone Bit3 7/8 ,5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 ... Tooth Tricone Bit3 7/8 ,5 1/2, 6 1/27 7/8,8 1/2,8 3/410 5/8,12 ...