These innovative rubber lugs are featured on many of the women’s boots we carry from The North Face. Attached to the durable outsole of the boot, this rubber is actually temperature sensitive. As opposed to vulcanized rubber, which is treated to maintain its elasticity in various conditions, IcePick™ Rubber hardens, as conditions get cold, and softens in warmer climbs. When snow and ice are packed tight and frozen hard, these stiffened lugs work to help punch through those layers, and create grip on snowy surfaces. As conditions warm, the rubber softens and becomes tacky, for stability on slippery or wet surfaces.