Painful heels? This 100% medical grade silicone heel cup reduces the stress to the joints and spine even under constant pressure. A 40% shock absorbing effect is achieved by this product. The blue coloured silicone is a softer grade of material to improve effectiveness. Fantastic for everyday use and very useful in reducing the shock that can result in painful heels when pounding the tread mill in the gym, or out running! Fit them to your trainers as standard! The heel cups are hypo–allergenic, resist bacterial growth, are non toxic and have a long life.(Use cold water and soap to clean)