Love the revised proton - Arc'teryx Proton LT Jacket - Men's

Such a great breathable insulation layer. Works from the mountain to the office building. Fits like all Arc’teryx pieces; if your slender and long armed you can’t find a better fit. I wore a proton and a gamma Mx all day skiing and was neither too hot standing or too cold on the chairlift, imo the jacket is a better mode than the hood but ymmv.