The strength of Pandora Jewelry is the unique patented threaded system.
Each bracelet / necklace is divided into sections by small threads.
Each bead / charm is equipped with interior threads, which allows you to screw individual beads / charms and spacers onto any segment in the order you desire.
The beads / charms move freely and rotate slightly with your wrists' movement. Accessorize your bracelet / necklace with clips and a safety chain.
U.S. Pat. No. 7,007,507.