I bought three of these for downhill skiing ... XL for my husband, M for me, XS for my 3 year old. Everything fits well, although the XS is still a bit big for the little guy. He doesn't like it covering his nose, but when he's a bit older he'll appreciate it on the colder days. Mine and my husband's fit well and they're very comfortable under ski goggles. I find the vent holes over the mouth can be kind of cold, so on the coldest days I still use my old balaclava underneath to cover my mouth. These work well either way because they velcro together behind your head - Easy to put on and remove without having to take off your helmet. The neck fleece part could be a little longer all around. All-in-all, very comfortable and effective.