It's called a 'Pinch' and it works best with a balaclava, to replace face masks.http://www.pinchoriginal.com/catalog/default.php
If you remember the hard-plastic nose masks that clipped onto goggles back in the '80s (my Carreras still have the pin holes for these), they are an exact fleece replacement.
reduced goggle fogging over face mask use
no ice buildup in mouth area
You kind of have to match up the upper profile to the lower contour of the goggle AND the length to your nose - small face and tall nose bridge is not a good combo for these.
They can tear up the goggle foam when removed, especially when the goggle is still cold and there is ice in the Velcro. EDIT: there is almost always ice in the Velcro.
You still should have a balaclava.