... rubber O-ring provides adequate sealing for bearing durability. More size Model114, 126, 117, 127, 437, 517, 537, 617 ... o-rin provides adequate sealing for bearing durability .5.size and model we can provide: 60mm,65mm,76mm,93mm ... .9mm(6 3/8”),165.1mm(6 1/2”)190.5mm(7 1/2”),193.6mm(7 5/8”),200.0mm( ... with you !!!PLs add this formation in your inquiry.1) the size of the tricone bit2) the IADC tooth model, ...