Great mountaineering layer
I used this jacket as my primary "working layer" on my Denali climb this past spring. It was everything I had hoped for from base camp to summit. Nice long pit zips when needed and good wind protection when the weather was bad. For added warmth underneath, I wore a Patagonia UL down hoody and that was practically all I needed while climbing for 3 wks on Denali.I cannot recommend this jacket enough. I bought the Medium so I could layer underneath. I am 5'5" and 125lbs but have very wide shoulders so I rarely fit into a small.