Weathershedding
It’s hard to beat the Montbell Peak Shell’s fully seam-taped, 3-layer waterproof construction. The “alpine cuffs”—partially elasticized, partially Velcro-adjustable—do a nice job cinching at the wrists to prevent rain from leaking in.

Breathability
For a jacket rated at 20,000mm, the Montbell Peak Shell ranks high on the breathability scale. The fabric itself feels thick and impermeable, but with the help of sizable pit zips, testers never found it to feel clammy on the inside, even during hard-charging efforts. 

Function
The hood feels excessively roomy—though it’s easy enough to cinch down snug around the face with two-way adjustment cords and a Velcro strap at the back of the head. The dual zippered hand pockets sit unusually high, which is nice for helping stowed accessories ride a bit closer to the body, rather than banging against the stomach.

Fit/Comfort
The Montbell Peak Shell runs quite large—likely because it’s more of a lightweight hiking or backpacking shell (designed for layering underneath) than a running shell. If you are the type of runner who prefers to wear your rain shell over your hydration pack rather than under it, this jacket is for you. The crinkly ripstop nylon feels a touch stiff and makes a good deal of noise while running.

Packability
For a hiking or backpacking shell, it’s quite light and packable. For a running shell, it’s on the bulky side. It does come with its own stuff sack—a nice touch, though not one testers used while trail running, instead opting to fold a jacket under their hydration pack’s external bungee cords for easy access.