The Atomic Hawx Ultra XTD 105 BOA W Alpine Touring Ski Boots add a long overdue 105 flex to the super popular Hawx Ultra XTD lineup. Perfect for advanced to expert skiers looking for all-day comfort in the backcountry, or those wanting a bit more flexible platform for technical skiing and tight quarters, the Ultra XTD 105 BOA® is one of the best options available for combining lift-served precision with backcountry flexibility.