Review (5/5): Important travel item if you like to breathe
I appreciate the fact that it is washable and re-usable. I like the bendable nose-wire (sewn in) because noses come in different shapes so this achieves a pretty snug fit. Okay, so it probably doesn't filter out ALL the particles but it keeps me somewhat more comfortable. While traveling away from my air-filtered bedroom with my dust-proof bed-linens, I wear it to bed in hotels. It also kept me more comfortable while riding in an open car in a fume-filled foreign city. (<=The non-asthmatic man sitting next to me felt nauseated by the end of the ride and I was just fine and didn't smell anything once I put it on !!)
It does look like a man's stripper thingy when you hang it to dry in your hotel bathroom, which probably causes the maids to scratch their heads, but it looks just fine once it's on my face.
Even though it probably isn't true-HEPA quality it helps me out and lets me function. Combined with being able to repeatedly wash and re-use it, I consider it an important possession in my travel-kit.