Surgical steel click closed septum or daith clicker. Inside opening is 9.5mm while outside is 15.3mm wide by 13.1mm high and has a wearable bar length of 8.8mm in 16G. Bar is surgical steel while link is brass with ion plated when colored.
Because brass contains copper, it can oxidize with moisture or skin chemistry and leave a harmless greenish tint on the skin. It isn’t an allergic reaction, but it does make these pieces better suited for occasional or event wear rather than daily use.