The Gold Button is about 11mm in outside diameter. The 14K Gold we use is; Solid 14K Nickel Free Gold. We use Palladium instead of Nickel in the Gold to help insure you of a healthy piercing. The Gold is available in either; 14K Yellow Gold or 14K White Gold and all of our Gold is 100% Solid. No Hollow balls that crush with us. All of our 14k Gold pieces are Internally Threaded for your comfort.