CliC Flex has a revolutionary new redesigned headband - part TR 90 flexible material and part rubber with wire core. This allows the wearer to adjust the depth and width of the headband for a custom fit, all the time. Like all CliCs, this frame uses CliC's patented front magnetic closure and integrated rear head/neck band. When you need the glasses, you raise them up and they "CliC" together with a strong magnetic closure. The headband keeps them secure on your head with no risk of falling off. When you do not need them, simply open the front and lower to your neck. The rear band now keeps them hanging conveniently around your neck so they're ready when you need them... with no chance you're going to lose them somewhere. Stop losing your glasses by setting them down and walking away ! Now they're always with you --- and ready whenever and wherever you need them.