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Smartwool PhD® Ultra Light vest
Material: Shell: 100% Nylon. Trim: 54% Merino Wool, 46% Polyester.
Weight: 4.7 oz
The main thing you may notice with this vest is that, well, you probably won’t notice it at all.
The PhD Ultra Light vest by Smartwool feels feathery from the moment you put it on: it does not add any bulk to your layering system and it fits comfortably on the torso. This vest stands out because it does not have any fill (down or otherwise), which keeps the bulk of an extra garment to an absolute minimum without sacrificing warmth. Plus, it easily packs down to the size of a baseball—small enough to fit into a running belt or a small pack.
The PhD vest consists of two materials: a merino wool/polyester blend that is warm and breathable, and a light, water-repellent nylon shell that keeps wind and light rain at bay. This model also sports a hood, which comes in handy for when that springtime breeze picks up. The shell has an opening in the back that allows excess heat to escape, yet it is not drafty due to the quick-drying Smartwool merino layer. The vest has a single breast pocket for easy access, and is otherwise streamlined and simple.
This vest is best for when you want a bit more core warmth on the lighter end—it keeps the chill out, but you don’t have to worry about overheating. Between packability, breathability and function, this is the ultimate runner’s vest for when you need that in-between layer.
—Jacky Thompson is an avid mountain and desert trail runner. When she isn’t rock climbing, running, foraging or frolicking outside, she can be found practicing yoga and playing music.