Sabona Athletic Bracelets feature the combination of 1200 gauss magnets and minus ion producing materials. Samarium cobalt magnets, each positioned bio north against the skin, will not rust from body moisture or as the bracelet is washed. Titanium material producing minus ions is inside the stretch fabric. Sabona Athletic Bracelets will stretch but snap back to the original size. You can wear them snug or loose, so choose your size accordingly. Sabona Athletic Bracelets may be hand-washed in mild detergent. Sabona Athletic Bracelet sizes are XS (5.75?), S/M (6.75?), and L/XL (7.75?).