Product details:

Layering isn't easy, but The North Face's Women's Ventrix Insulated Jacket simplifies that hot-cold-hot rollercoaster you've been riding since the trailhead. This synthetic insulated coat uses laser-perforated panels under the arms and on the back to dump heat during high-output activities, so you can put it on and leave it on. The slim fit slides right under your hardshell when the snow starts to fall, and the polyester-based insulation retains its warmth even if it gets a little wet.