This add-on is offered for those who enjoy a longer chain length. The length of the chain will be 13". This can be added to you order for ONE necklace. For example, if you wanted to purchase a Black Obsidian necklace but with a longer chain, then this will have to be added on to your purchase. Please note that if you want MORE than ONE chain, you will have to add this product to however many necklaces you wish to purchase. For example, if you wanted to purchase a long Clear Quartz Gold Necklace and long Amazonite silver necklace then this product will have to be added to your overall order twice! Additionally, this option can be added to the Mystery Box as well!!