The Gore Windstopper X-Fast body and knit stretch windproof panels to the sides and shoulders keep the wind out of the Mortirolo V Jacket, meaning you retain more body heat as you ride. To ensure you don't then overheat and wet out from sweat, Castelli uses their highly breathable Thermoflex fabric to the rear, allowing heat and moisture to escape. The result is a highly versatile jacket that can take on temperatures from cool to mild and a wide range of training intensities in colder weather. An easy-sliding YKK front zipper makes control of ventilation a simple one-handed affair, while out back three pockets provide ample space for all your essentials. A large reflective panel on the back, ideally positioned below the pockets for maximum visibility, grabs the attention of fellow road users when you're caught out after dark.