Used for one day and the metal wire fell out of the rubber. Now it will not stay in the rubber. Worthless!! I wouldn't buy until the manufacturer uses something better to connect the wire to the rubber. Its too bad to. I really like these compared to other designs that use materials that retain water and keep your neck wet and heavy feel. You hardly notice these are on. Overall design is there. Just need to think of something to attach those better and I would buy another one.