FuelCell foam provides a propulsive sensation to propel you forward. Achieve a fast, effortless, and precise fit with the BOA Fit System. The TRACE FIBER upper technology utilizes digitally adjusted fibers to offer an innovative fit, function, and style. The Energy Arc incorporates advanced carbon fiber plate geometry with strategically positioned midsole voids, enhancing energy storage to provide a substantial amount of energy return. The shoe features a built-in tongue for a secure, breathable, and convenient fit.