Order up one size. Not a lot of baggy room in the arms, but a very nice light layer of wind protection to go over a shirt or warmer base layer. Packs extremely well and feels like nothing while wearing. No pit zips so venting is just by the main zip. I believe this is a nice piece to make breathable layers more wind resistant without feeling too bulky. A nice pick up. Get the blue, as the orange is very "see-through" and reveals what is underneath. I bought BOTH colors and like them very much.