Okay, i was a little weary of these jackets or 'sweaters' as some retailers call them... but after buying this one, and wearing it in weather that was down to about 10 degrees in the evening, i can now attest to it's great warmth and comfort. I am a medium sized guy, 38 chest and 5' 9'', the Medium jacket is a great fit. Highly recommend this jacket as a layer piece or top shell for mild to cold weather without rain, it's only water resistant, not waterproof.