The two outer ball studs on this 3 piercing, earring combo are attached to the central stud via a pair of 2.5 inch long chains. Each of the 2.5mm diameter ball studs requires its own piercing, usually 2 on the outer ear and one on the inner ear (for example a tragus piercing and 2 lobe piercings) and they are fastened with their butterfly backs. This version has been made from gold plated sterling silver, but other metal options are available too.