Features carbon light sole made of carbon and fibreglass with a stiffness index of 100 and 4 vents for constant airflow nw speedplay adapter compatible for the lowest stack height between foot and pedal ultra snug fitting upper with biomap aero overlap construction and micro perforations reduces aerodynamic drag slw2 dial the only one with step by step and full release in a single button integrated heel system containing directional fibre prevents any slipping extreme air evo footbed provide