Comfort and Performance. A ski boot for good skiers that incorporates Twin Frame technology to provide the rigidity you need for greater control and enhanced responsiveness. This is combined with an unrivalled foot-hugging fit for optimum performance on the piste. PU bi-material lower shell and upper cuff construction. The Sidas Booster Strap ensures optimum hold of the upper cuff and tongue as well as easy tightening. The 24mm oversized pivot reduces the interaction between the lower shell and cuff for outstanding precision and direct power transmission. The angles have been modified to optimise the foot position and provide better heel hold for increased precision.