Works perfect under your helmet to help keep your face warm and to keep extra dust out of your mouth/ears. I wear a size medium helmet and it fits perfectly. If you are a XXL type head guy it may be too small.
The motley tube is inexpensive, takes very little room in my saddle bag, and is handy for cold days to keep my neck and chin warm. It also works great to keep my head warm when out camping with the motorcycle.