This jacket is great.  I bought it for a trip to Kauai where it randomly rains for a few minutes each day.  Very lightweight, can be more than ounces in weight.  It is unlined- so very thin for warmer days, and has a breathable placket on the back.  There is a hood that actually fits into the collar so it can be hidden away.  My favorite feature is that it is packable into its own pocket, so basically you turn the pocket inside out, and then squish the jacket into it--it fits right in with room to spare so it can be easily stuffed into a backpack or purse.  I added a carabiner to the carry loop so I could click it onto a belt loop.