Hejian Yinhai Rock Bits Manufacture Co., Ltd is a professionalTricone Bits maker with more than 10 years experience. Our productis from 61/2\" to 20\" with IADC code 517, 537, 617, 637,515.Our bits holds a very good reputation in water drilling market inChina, while the price is more competitive than Golden Kingdreamand Volgaburmash.Leave me a message or send me an email to : bitschina at gmail dotcom