The La Sportiva Men's Synthesis Mid GTX Hiking Boot feels surprisingly breathable for a shoe equipped with waterproof protection. That's because Gore Tex's latest and greatest Surround technology allows 360 degree breathability. Compared to previous waterproof, breathable membranes that only cover the shoe's upper, Surround technology wraps a membrane around the upper and sole. You'd think this would decrease the shoe's overall breathability, but La Sportive fused a sole with mesh inserts that enhance the shoe's breathability while still providing a truly waterproof experience. The Synthesis also features a well ventilated AirMesh upper with Nano Cell technology for better support. STB technology unifies the midsole to the upper for a longer lasting performance, and the PU leather toe protects your foot from protruding rocks. Underfoot, the Synthesis uses a cushy compression molded EVA midsole with cradling TPU inserts that keep your foot prime for miles. A shoe this good deserves the best sole, which is why La Sportiva used Vibram's superlight Nano rubber, and there's also an Impact Brake System for an improved downhill performance.