Tecno 3: Allows you to close the shoe quickly and easily, adapting the upper part to the shape of the foot. The anatomically molded plastic shell stabilizes and supports the heel and helps transmit more power without dispersion. Sidi cycling shoes are equipped with a non-slip, replaceable, polyurethane insert in the heel to facilitate walking. Made of nylon, enriched with carbon fiber, the Sole Millennium 5 is strong and less subject to any change after prolonged use.