NNN BC(Rottefella/Rossignol). Quick Dry Liner. Dual Density: Injection of two plastics with different densities into the same mould. Precise movement control. Reduced skier power loss. Optimized ski/snow contact. Speed Lock System: Technical, precise and simple to use- even with gloves!. Thermo Adjustible Fit: When heated, the special materials inside the liner mould to the shape of your feet to adjust inner boot volume. Comfort. Precision.