Rebelling against a winter of indoor training is the Castelli Alpha RoS 2 Jacket, a feature-heavy barrier against nature's bite, ensuring the miles are logged even in the harshest conditions. As Castelli's premium winter jacket, the Alpha RoS 2 gets a double-layered Alpha construction with an inner insulation layer and outer Gore-Tex Infinium wind and water barrier. The layers provide protection down to 23 degrees F and superior wind and water resistance to brace against pocket showers or a ride-long drencher.Castelli manages to engineer subtle and effective traits into the Alpha RoS 2 that, at first glance go unnoticed, but act as welcomed finishing touches you'll appreciate during mixed weather riding. Further adding to the comfort and warmth characteristics are the high neck, which prevents cold air rushing on the chest, and the double layer cuffs that seal out water and wind and allow for expert fitting under gloves. A water-resistant zipper and taped shoulder seams seal out areas that are prone to water ingress, while discreet back flaps vent out heat to maintain comfort on rides up to 50 degrees F and during intense interval sessions. Castelli adds drainage holes to the pockets, which provide an extra dose of security compared to the mesh openings of previous jackets. A zipper side-pocket corrals valuables for the long haul.