... :2000 certified 3.OEM service offered, Design Service Offered Crystal Resonator Shell1.matrial:copper,iron,aluminium,Kover2.specification: 55*22 ... Treatment:polishing,electroplate,electroless plating,electrolytic,passivation,etc.Plating Type:Nickel Plating,Tin Plating,Zinc Plating,Gold plating,Coating ... machine,Turning machine,Grinding machine,etc.Certification:ROHS Compliant Crystal Resonator Shell