... service offered, Design Service Offered Crystal Resonator Shell1.matrial:copper,iron,aluminium,Kover2.specification: 55*22 36*22 36*27 20 ... Material:Brass,CRS,Stainless steel,Kovar,Copper-Nickel-Zinc Alloy,Iron nickel alloyProduction process:Stamping,Forming,Cutting,Punching,Positioning,Sintering,Welding ...