The C.A.S. Tongue is a great addition to Tecnica C.A.S. Fit system. It is a fully customizable tongue that allows for personalization of the fit in the shin and instep area. The tongue can be thermoformed in few minutes to perfectly match the shape of your shin, which is ultimate solution to alleviate pressure points and pain in the shin and instep area. The C.A.S Tongue also features a C.A.S. material instep insert that can be milled if instep additional pain occurs. Thanks to the Velcro attachment, the instep volume can also be customized to provide a constant and precise match between your shin and the boot which results in better power transmission, feeling and comfort.