Whether you're cross-country skiing or hitting the slopes, the CRT liner adapts to your feet and provides maximum comfort thanks to its thermoformable technology. The thermoforming of this liner must be done by a professional. The result of 2 years of development with the best boot fitters. The internal structure, with an adjustable thickness, guarantees comfort and precision after moulding. The removable tongue is thermoformable and can also be replaced with an injectable Sidas tongue.