The Arc'Teryx Squamish Hoody is a nano-weight windstopper. To be clear, it's not insulated at all and is not intended to be a waterproof rain shell. Of the other ultralight windbreakers on the high-end market, it does have the best water resistance (has a good DWR coating) and will stand up to a light drizzle for over an hour or so before wetting out. But all of the jackets in this class will wet-out under a real rain in less than 10 minutes.

I can't overemphasize how thin and lightweight this jacket is. It feels like it's hardly thicker than Saran wrap. But it is made with a ripstop fabric and has some stretch. This will easily fold down to fit in a purse or cargo pocket.

Best use would likely be for chilly days on the ferry or beach, and hiking or biking. It has a pretty snug athletic fit well-suited for cyclists, so if you want to wear a fleece pullover underneath, you should order up one size from your usual.

Verdict: Very pricey for the level of protection it provides, but for the ultralight athlete who wants the best nano-windshell on the market, this is a solid piece of gear.