"Created using lightweight, heavy duty aluminum chain, premium O-ring hardware and a matte black moon. Choose your own O-ring and chain finish.  This slip-chain collar has a set size of 25" long.  Simply push the moon through the O-ring to wear. Please note that the moon may slip through the O-ring if the O-ring slides all the way down during wear. This chain choker is not created to be used on animals.Width: 5/8""