We have been stocking this brilliant face mask for years because it is simply the best of its kind. It is extremely comfortable to wear & the nose slit, & perforations in the mouth area allow you to breath freely while the snug fit keeps you from freezing whilst skiing or climbing in foul weather, it also works well under a climbing or biking helmet. The rear panel is made from Polartec Powerstretch to give a close fit & seal, while retaining easy freedom of movement. The attention to detail makes this little gem by far the best facemask we have seen. Power Stretch® insert for ideal freedom of movement Reliable protection against cold & wind