Tercel Roller Cone bit
The Tercel premium roller cone bit line has at its foundation precision machined bearing races that are matched to provide the optimum fit and finish for extended operations, even with parameters of higher RPM and heavy WOB.

The bearings are designed and machined for reliability and consistency. Combined with a seal system designed to provide optimal compression on the O-ring and a specially formulated extreme pressure synthetic lubricant that extends the bearing life, the Tercel PRC system delivers a reliable solution for all drilling formation challenges. Available in both milled tooth and TCI variations.

http://www.terceloilfield.com/products/drill-bits/roller-cone/premium-bearing-roller-cone/