Here's something you don't see every day - a brand new closure system in alpine ski boots hasn't really happened since Henke introduced the first buckle boot back in the 1960s. The Salomon S/Pro Supra BOA 105 W Ski Boots not only rock the new BOA® fit system, which brings a new level of comfort to wider feet and taller insteps, but instead of leather they are built of Custom Shell HD heat-moldable Polyurethane, making a whole new world of custom fitting available to skiers with anything but average-shaped feet. The S/Pro Supra Boa® 105 has the perfect flex for advanced to expert skiers who don't need the stiffest boot out there and want a versatile, all-mountain/all conditions flex.