Trion:Z Necklace Elite with CO Pendant (Various Colors/Sizes) Pure Ti-22 Titanium Ferrite Permanent Magnets Adjustable Magnet Capsule. Water & Sweat Resistant Silicone Design 2 Sizes available - Medium 47 cm (18.5") or Large 55 cm (22") Golf Tees Etc are an official Trion:Z dealer