The Power Balance silicone wristband comes equipped with two, visible Power Balance holograms. The 3mm thick wristband is made from 100% Surgical Grade Silicone that is extremely durable , featuring a 40% stretch feature for extra stretch over the hands. It is built to last.  Available in sizes: XS (16cm)  S (17.5cm), M (19cm), L (20.5cm), XL(22cm).