When we need a boot that allows us to climb skin tracks with perpetual motion, we trust the Dalbello Quantum Free Ski Boot. These boots prioritize uphill performance while still considering downhill control by combining an average 100mm last with a fully capable walk mode, and a stiff 105 flex rating. The Reinforced Dual Link Walk mode creates a 65deg range of motion that flexes both forwards and backwards so that we don't waste any energy in our stride. The composite polyamide material further offers uphill comfort by shedding as much weight as possible, without limiting torsional rigidity.