CFS is the bottom layer of ECCO's removable insoles. The top layer can be made of leather, Poliyou®, or a combination of leather and textile.

A material specially developed by ECCO to promote improved foot comfort.  It has good air circulation. The material is open-celled, i.e. a pump effect is produced during walking that increases the supply of fresh air to the feet, enabling them to stay fresh. It also has an anti-bacterial effect. The material neutralises the bacteria occurring in moisture and sweat, reducing any possible odour. The shock-absorbing effect protects the lumbar region, coccyx and spinal column. The material is also soft and follows the contours of the foot when walking. It is a durable material so that it does not lose its shape or special effect as a result of use. It is also recyclable.