NN International began to invest in China in 1997, focusing on top drive equipment repair, rental & on-site service, parts supply, technical training, top drive sales and purchase service business. It has established three entity companies and a marketing company. At the same time, it created " " top drive professional service brand. Up to now, NN International has set up a wide range of business contacts with oil companies at home and abroad and has carried out repair projects of top drives in Sudan , Saudi Arabia , Iran, Yemen, Nigeria, Ecuador , and other countries and regions .It has established top drive repair & service stations and spare parts reserve storages , forming a relatively well-established global service network accessories support systems .