Step into a fashionable boot with authority and presence, like the Indigo by Clarks Mission Alfa ankle boot. This beautifully designed women's boot features a rich leather or oily leather upper with an asymmetrical, antique-finish zipper and leather pull accent. The chunky Leawood heel and lugged rubber sole finish the look of the Indigo by Clarks Mission Alfa boot with stylish details and rugged wearability.leather. Rubber sole. Shaft measures approximately 7" from arch. Heel measures approximately 2.75" Boot opening measures approximately 10" around. Lightweight ortholite footbed adds cushioning to reduce foot fatigue. Rubber outsole delivers long lasting durability on a variety of surfaces. Soft Leather breathable upper.