The Definitive Facemask is made from a blend of bamboo rayon and merino wool. I am a yowie type of guy, and the Le Bent Facemask was just as good. It is a bit thicker than the yowie, so it is suited towards lower temperatures. It fits a tad looser than the yowie, but is still a nice snug fit. It sits nicely beneath a pair of goggles without any discomfort.
It does not let your breath out quite as well as the yowie, so if you are waiting in the lift line after a solid aggressive run, the outside of your goggles will fog up. It does wick away the moisture very well though, the material dries out very quickly after getting wet from your breath.
Overall, if you are looking for a slightly thicker yowie, this is an excellent choice. I can say I am definitely a fan of the rayon merino blend.