In this jewelry, 3D means three dimensions: two different sides, i.e. two different pieces of jewelry, one side on the other day and the other side on the second day and only the selected side is visible .The third dimension is the interior where you can put your own perfume if you want! The heart jewelry is high-fired pottery  4.5cm  length .The jewelry includes an adjustable leather strap and a silver-plated collar that are easy to change  according to the way I live.