1.metal case: 2.made of steel sheet or AL sheet 2.competitive ... .high quality and best service 4. OEM service metal case : Product Type metal case Materialsteel sheet, Al sheetMachining typestamping, punching, bending, welding ... plated;3)Surface treatment:kinds of plating(Zinc,Nikel,Chrome,Tin,Ag);Painting,Powder,Anodizing,E-coating,Silkscreen,Heat treatment,Black ...