Serenity Magnetic Necklace with Paris at Night adorned with Crystals from Swarovski? Ball Marker inset in the piece. This designer style necklace is so gorgeous that nobody would ever know you're wearing a ball marker! Any of your Navika magnetic ball markers will pop in and out of this functional and fashionable necklace. Chain is adjustable between 16-18 inches and is stainless steel so it will not rust or tarnish.