It's engraved on very high quality metals so that it has an incredible shine that you will love every time that you look at it. Disc is 0.9in (22mm) in diameter, with a 18in (48cm) chain and a 4in (10cm) extension. Gold plated pendants are plated with 18k gold. Made with high-grade 316L stainless steel, which will not oxidise or turn black. Of course, all jewelry is nickel and lead free and will not give any allergic reaction. Products are mede in the US.