Shimano's SH R171 Cycling Shoe offers pro level features at a price that accommodates a recreational cyclist's pocketbook. To start, Shimano uses a lightweight and stiff carbon fiber for the SH R171's outsole to maximize power transfer to the pedals. Shimano's Dynalast construction also increases your pedal efficiency, by creating the optimal pedaling angle on either side of the up swing. Shimano does this by lowering the toe spring and heel section in relation the arch and metatarsal areas. The SH R171 features a stretch resistant, and highly ventilated, synthetic leather upper that will provide a consistent fit all day long. In addition to this, Shimano's new ratcheting buckle closure lets you dial in the most precise fit by allowing fore and aft adjustments. And with the R171 you won't need to crank the straps down to prevent slippages, because Shimano's insole stabilizes your foot and keeps your heel comfortably in place.