This two necklace / pendant set is an ideal way to keep a constant reminder of your best friend. Each pendant comes with its own 16 inch ball chain and with a half sun pendant. One pendant says "Best" and the other says "Friend". The inner material if the pendant is a special epoxy material that reacts to your body temperature. As your temperature changes, so will the color of the pendant. These pendants are known as "Mood Pendants". The various colors that reflect your mood are: Purple: Anxious, Yellow: Nervous, Orange: Cool, Green: Calm, Blue: Happy, Dark Blue: Passion.