stainless steel base cover: 1. Diameter: 16mm, 25.4mm, 31.8mm, 42.4mm, 48.3mm, 50.8mm, 63mm, 76mm2.Thinkness: From 0.5mm to 2.0mm.3.Material: SS201, SS301, SS304, SS316.4.Finish: Polish, Satin and Golden5..Package:individually in plastic bag,standard carton for outter packing. 6. Certificate: ISO9001-2000, Products quality certificate etc, 7. test report of base cover Steel gradenationalstandardCSiMnPSNiCrMoTiN≤≤≤≤≤(Austenitic Type)0Cr18Ni9CNGB0.07120.0350.038.00-11.0017.00-19.00≤0.10USAISI0.080.7520.0450.038.00-10.5018.00-20.5000Cr19Ni10CNGB0.03120.0350.038.00-12.0018.00-20.00≤0.10USAISI0.030.7520.0450.038.00-12.0018.00-20.000Cr17Ni12Mo2CNGB0.08120.0350.0310.00-14.0016.00-18.502.00-3.00≤0.10316USAISI0.080.7520.0450.0310.00-14.0016.00-18.002.00-3.0000Cr17Ni14Mo2CNGB0.03120.0350.0312.00-15.0016.00-18.002.00-3.00≤0.10USAISI0.030.7520.0450.0310.00-14.0016.00-18.002.00-3.008.Relative products photoes: