Sidi's 4-Bolt SP Carbon Soles maximize your power transfer, ergonomics and comfort. Made of tough T700 carbon, they actually deflect only 1.5mm when 110 pounds is suspended from the tip, and Sidi eliminated the need for cleat adapters, which puts your feet 4mm closer to the pedals. These advances maximize your pedaling efficiency and there's also 6mm more cleat adjustment so you can find the perfect position. These soles are lighter too which saves energy. Plus they flex just enough to prevent pressure points and ensure top comfort no matter how far you ride. These sweet soles are also hand made in the same Italian factory as Ferrari and Ducati parts!