... .ISO9001:2000 certified 3.OEM service offered, Design Service Offered Crystal Resonator Shell1.matrial:copper,iron,aluminium,Kover2.specification: 55*22 ... .Major Equipment:Stamping machines,Punching machine,Cutting machine,Sintering machine,Seam welding machine,Spot welding machine, Milling machine,Turning machine,Grinding machine,etc.Certification:ROHS Compliant Crystal Resonator Shell