For its premier mountain offering, Lake used top shelf materials and technologies to build one of the finest bike shoes available. From the soft, durable, kangaroo leather uppers to the carbon fiber outsole, Lake didn't mess around with the MX331. Of course, materials are only half the story. Lake also poured its best technology into the MX331. For efficient power transfer, Lake shaped its carbon fiber sole with its CFC Race Last. The outsole uses Lake's cleat pockets and modular rubber treads for traction. Closure is handled by the BOA PushPull retention system. BOA provides an unlimited range of volume customization, a complete lack of pressure points, and a weight reduction of nearly two thirds, compared to traditional systems. Inside, you'll find a fully moldable heel cup to virtually eliminate heel slippage.