Patagonia Women's R1 P/OFeatures: Durable, stretchy and breathable Polartec Power Grid fabric is hybridized with our Capilene Thermal Weight baselayer fabric to reduce bulk and make this lightweight layer even lighter Hybrid design boosts warmth around your core while improving underarm breathability and venting extra heat Hybridized fabrics provide outstanding stretch and increased mobility, especially when reaching overhead Zippered left chest pocket with a zipper garage