The soft instep closure system is a strap positioned on the instep, contoured, soft and anatomical coupled with soft material for added comfort. it distributes pressure evenly over the instep and adjusts on both sides to have a perfectly centered position of the strap depending on whether the instep is basso or high. the system eliminates the need to use a spacer. soft instep closure system is replaceable.the tecno-3 mechanism allows the entire length of the shoe to be closed, adapting the upper to the shape of the foot and thus achieving a customized fit. sidi's reliable, fully replaceable closure systems have been improved with a new type of cable, which allows quick adjustment with ease. like most mechanisms used by sidi, the tecno-3 lever is sturdy and replaceable.the heel is integrated, newly designed and lightweight, reinforced to prevent deformation after prolonged strain and pressure. anatomically shaped, it stabilizes and supports the foot in pedaling. reflex inserts on the heel provide added safety for the athlete on the road, helping to signal the cyclist's presence in low-visibility conditions.sidi cycling shoes have a replaceable polyurethane heel heel.the carbon composite 20 outsole is made of injected nylon and carbon fiber. nylon allows the technical characteristics to remain unchanged over time. the result is a lightweight and rigid sole. the central part of the sole is graduated, with a scale in millimeters, to facilitate the correct attachment of cleats. equipped with a replaceable polyurethane heel counter.