It's been celebrated as a "perfect fit" and a "wildly versatile piece" by professional riders. That's because it has amazing versatility, wears like a jersey and works as a true 3-season outer layer. The ES Jacket is further enhanced by the pairing of Polartec(R) 's Power Shield Pro(R): their top of the line, ultra-breathable windproof and highly water resistant (5m) membrane softshell fabric with luxuriously soft and breathable Italian Superroubaix. All that tech means wind cutting-non-flapping awesomeness that looks sleek as hell. The functional layer of Power Shield Pro(R) enables the fabric to block 99% of the wind but allows enough air to circulate to keep you from overheating. Comfortable down to 30 F (-1 C), the jacket hits its stride in the days between Winter & Summer when comfort is needed amid ever-changing weather.