Crystal Chameleon Ball Marker Magnetic Necklace with the Horseshoe Gold Plated Swarovski Crystal 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 25 mm magnetic ball markers will pop in and out of this functional and fashionable necklace. Chain is adjustable between 18-20 inches and is stainless steel so it will not rust or tarnish.