The Alpha 150 W Jacket is the jacket made so you can ride all winter long. Comfortably. No excuses. We set out to make the ultimate winter riding jacket — a singular goal to make the best jacket we could, featuring the best fabrics and innovative construction, and ensuring comfort in the widest range of conditions, including cold and wet. The Alpha 150 is the result of 12 years of continual refinement of a concept to keep you warm and dry, both inside and out. New for 2025, the Alpha 150 W Jacket now uses Castelli’s exclusive Polartec® AirCore™ fabric for unmatched breathability in a windproof and rainproof fabric. On the inside, Polartec’s Alpha insulation provides warmth while enhancing moisture management. The stretchy close-to-body fit means you don’t feel like you have a full winter jacket on. This jacket is ideal for cold, dry days yet can stand up to everything except all-day driving rain, when you’ll probably reach for a rain shell. The fact that it uses recycled yarns and is PFAS-free is a bonus feature of the best winter jacket we’ve ever made.