Workover Rig, Flushby Unit, Rapid Service Unit manufacturer / supplier in China, offering 12-1/4 Inches IADC517 Water Drilling Bit Rock Roller Bits Tricone Bit for Well Drilling, API 251mm IADC517 Rock Roller Bit TCI Tricone Bit for Oil Drilling, TCI Bit API 7-1 6-1/4" Tricone Roller Bit Three Cone Bit for Well Drilling and so on.