We are the?agency of the largest state-owned enterprises---GuiZhou Gaofeng Petroleum Machinery(such as drill pipe, drill collar, stabilizer and mud pump)?in this field of China,?which products?share 50% market in China. With professional project, design and inspection department, all of our products manufactured strictly conform to API standard, and with material certificate, detection of defects report, heat treatment report, and quality certificate, and API association mark. Thus the quality is absolutely guaranteed as well as competitive price and good service.?