Montane Featherlite Velo Jacket
Here's what other sites are saying:
Montane engineered the Women's Featherlite Velo Jacket to be the world's lightest and most packable cycle specific shell. Weighing in at a barely noticeable four ounces, this shell weighs less than the spare tube you have in your pack. The pre-bent extra long arms and extended drop tail are specifically tailored to fit your body while it's in a cycling position. Super-breathable panels are incorporated in to the shell, allowing excess body heat to escape. And the Pertex fabric is highly wind-and water-resistant.