Had some big bugs bounce off my glasses and cheek, but only an occasional gnat in the mouth. I now carry my mask from carpenters bag, that I use when sanding spackle. No problems other night on trail; although may have looked a bit strange. Only use after sunset on trail. Bugs a plenty. Thinking those flu masks may be a bit more in style.
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BierHaus Bertolette Road Bike, built 2007
BierHaus SRT Trail Bike, built 2010
Fuji Mt. Pro - 2007