Size small however I am 6 ft 160 and as the pics show it fits me well.. That said I’m built like a biker. It has two layers in the front. Designed for intense outdoor exercise The arms are not tight which is nice as your arms stay comfortable. Sleeves are xtra long and can pull over my knuckles which is nice in the cold. No rear pocket 3 zip ones outside one interior chest zip pocket. Nice fabric for wind, water resistant though not a rain jacket. Breathable fabric. M3 is Marmots most breathable wind and water resistant fabric.