Sidi Kaos Air Shoes; Sidi Kaos Air Shoes; offering a high quality fit & technically advanced design Featuring Sidi's Millennium 4 Carbon Composite sole; made using a mixture of carbon & nylon offering more rigidity than the standard nylon sole The Soft Instep 3 Closure system is adjustable from both sides to evenly distribute pressure over the arch area The two other closure mechanisms allows the shoes to be adapted to your individual foot shape The reinforced heel will keep the foot in place whilst also avoiding the shoe being deformed