Not my listing, but wear a large in everything sitka makes. This is basically the waterfowl line version of the equinox/traverse. Equinox is in the whitetail line. Traverse is more of the western line. I am 6 foot and 185 lbs and I wouldn't want to layer more than a core heavyweight hoody under my equinox. A thinner layer under would be preferred. The high loft, compression resistant, fleece is not very slick so you can feel a bit bound up with more bulk under it. This is a good price.