The Synergy Sensor? 80 delivers a forgiving, comfortable fit without sacrificing powerful, all-mountain performance. Sensor? shells feature a 102mm "medium-wide" fit while retaining the contoured forefoot, strong heel cup and asymmetrical toe box. Sensor Fit technology addresses all of the common problem fit areas, providing an accommodating instep and more articulate ankle area for increased comfort, circulation and warmth. The Synergy Sensor? 100 is a versatile all-mountain boot with a forgiving fit for advanced to intermediate skiers.