Body-mapped to keep our layering lightweight and breathable the Norrona Warm1 Hooded Jacket just gets everything right for our trail runs hikes and other outdoor activities. This lightweight fleece features a 140g knitted polyester in front for light insulation to keep us warm with an even lighter 127g polyester mesh in the back and underarms for better breathability and moisture management when we start to run too warm. We like those moisture-wicking and quick-drying qualities to keep us feeling fresher and also appreciate the jacket's anti-odor treatment which keeps us smelling fresher too.