Layering for cool spring runs just got a whole lot easier thanks to the Mountain Hardwear Kor Preshell Hooded Jacket. This ultralight jacket has the stretch, breathability, and weather-resistance that you need to stay comfortable when you hit the road or trail in hard-to-guess weather. It's made with Pertex Quantum Air, a lightweight ripstop that sheds light rain and blocks moderate winds without sacrificing air-permeability. The result is a jacket that offers weather-resistant protection and won't pack heat when you start to work hard. The full-zip design allows for further ventilation and airflow if the weather warms up during your run, and if you find it's gotten balmy enough to shed your jacket completely, you can stuff it into its own hand pocket, stash it in a pack or pocket, and keep on cruising.