Outdoor Research Helium Rain Ultralight Jacket

From the website: The Helium Rain Jacket is an ultra-packable, lightweight, breathable, multi-use award winner, offering durable weather protection when the forecast calls for on-and-off-again sun, showers, clouds, and cool breezes. This is a great jacket that can tackle all conditions. It has served me well, and still has lots of life left. It is packable into the upper chest pocket and is about the size of 2 fists.