full grain calf leather front closure with elastic laces and closed lace hooks internal flap in elasticized lycra for a greater fit of the calf and closed on both sides to protect from dust, dirt and water customizable design with interchangeable straps rear elastic band for a tailor-made fit anatomical, antibacterial, thick and removable fuss bett integral zip slider cover micro-pierced calfskin lining exclusive air boost ventilation system rubber sole with anti shock system back ykk zip square toe