Silicone is , reusable and flexible, which can resile instantly after pull or pinch. Suitable for creating beautiful earrings, necklace, for chain and other jewelry pendants or pieces. Inside is smooth, which allows you to make smooth pendant and is easy to take out the pendant. Ball or cube is available for you to choose from and meet your different needs. Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid.