Changsha Longo Import & Export Co., Ltd is a professional manufacturer & exporter specializing in producing drilling rig,diamond core bits,reaming shells, core barrels, drill rods,casings and other are used mainly in mineral exploration, site investigation, water well construction and etc. Longo products are manufactured according to the ISO, DCDMA, CDDA, Metric and Chinese Standards to meet the different needs for the customers.So far Longo products have been exported to more than 50 countries.