This is best jacket have ever owned. It is simple in design, warm and incredibly light-weight. The jacket comes with a small carrying case about the size of a grapefruit — the entire jacket can be rolled up and deflated to fit inside. I stuff the entire thing in my backpack all the time (if I wanted to I could fit it in my pocket). I purchased the jacket while in Cape Town during their winter, when the temperature fluctuates greatly day and night (40° F – 75° F). I could keep it on pretty much all day without being too cold or overheating. In Cambridge, it serves as a perfect outer layer.