... is 58mm.Total 3 serials, 17",21"&25" CompanyIntroduction1. Our company has advanced technological equipments, all kinds of quality checking Equipments ... 16949.4. We have accumulated plenty experience and our company has been expanding by leaps and bounds.5. The annual productions are over ... to U.S.A, U.K., Germany, Italy, Japan, Swiss, Australia, and South-east Asia; ASTM, DIN, BS, JIS standards;3. Hope ...