All Attiva liners utilize lasts of women's feet to create the best fitting boots. A narrower heel pocket and wider forefoot offer a well wrapping, anatomic fit. 1. The heel is 2.5mm higher than the man's last, to support a woman's foot in a neutral position 2. Prominent instep enhances circulation and warmth 3. Narrower heel accommodates the woman's foot structure 4. Custom arch accepts both high and low arch types 5. Shaped metatarsal area adds support and comfort 6. Open toe box enhances blood circulation and warmth 7. Greater adjustability in calf area accepts a variety of muscle diameters