1,Tricone bit,rock bit,three tooth triconebit 2.certified by ISO,API 3.wide size code 4.best price ,delivery on time ... future through our consistent efforts.Tricone bit1.High-strength, high flexibility, high temperature, high wear resistance.2. High-precision metal seal.3. Locking roller ball ... adapt to the soft, medium and hard of various strata.7. Reasonable price and long working life.