No restricted breathing. The same as our FogEvator and the No-Fog mask and other similar products.
What we found, and I know many others also found is that by having the "fog treatment" attached to your skin works better than if it's attached to a helmet. The disign goal was to have the product maintain it's seal under all conditions. Now if you have the kids on a Sunday put-put it's no big deal but getting the sled in the air or really pounding a 5 mile rough stretch it becomes more important. First, as we all know, you heat up and sweat with increased activity. Second, the helmet, if you are getting "after it", will dance around a bit on your head no matter how tight the fit. Combine a moving helmet and a breath box attached to that helmet and you get a moving seal on that breathbox-which can lead to fog.
As mentioned, a good fog mask and balaclava work together well-we combined them-and got a few more benefits. First, it's easy to put on and take off. Second, we eliminate the headstrap which really improves comfort. Third, we eliminate the extra fabric over the ears where it was not needed for function but was required to provide a secure attachment point for the headstrap, which we no longer need!
I'm well aware that not every item is for every rider but we do hope our solutions will prove usefull to many.
Without snow, however, it's all just nonsense!