Sidi is the world's bestselling brand of road shoes, and the Genius 5 is the best selling model from Sidi. Its Lorica upper has all the upsides of leather with none of the negatives. Lorica is supple, conforming, highly breathable, and will not stretch. In addition, Lorica is water repellent, highly abrasion resistant, easy to clean and won't rot or dry out. Sidi combines Lorica with ballistic mesh to give you superb comfort, fit, and ventilation.The Genius 5 Pro Composite Women's Shoes are made with Sidi's Millennium 3 Carbon Composite sole. Unlike the Nylon construction of the Millennium 2 sole, the Millennium 3 is constructed from an injected carbon fiber in a nylon matrix. This provides 37% greater stiffness than the Millennium 2, and it's more durable to boot. One other nice detail with the Millennium 3 is its replaceable non-slip heel pad -- great for when you're click-clacking through Starbucks.Sidi adds a ratcheting Ultra SL buckle so you can micro-adjust strap pressure to ensure that the fit of your upper won't be too loose or too tight. The Ultra SL is mated to a soft Arch Compression Strap that more evenly spreads the upward stroke pedaling forces across the top of your foot. The Ultra SL buckle provides 4 clicks per uptake along with half-click releases, meaning that you can precisely tension the pressure of the strap.